On Monday, I attended an all-day reviewer workshop for Windows 8, Microsoft's next desktop operating system. And while it may be a while before I can adequately describe my thoughts about Windows 8, for now it goes something like this:

Microsoft president Steven Sinofsky previously described Windows 8 as a reimagining of Windows, a way to bring the software giant's most versatile product forward to address a new set of needs and usage scenarios. This is largely true, and it's hard not to picture future Windows versions jettisoning even more legacy functionality in a bid to drive Windows ever forward.

On the other hand, Windows 8 also presents the user with two discrete environments, one of which is new and pretty--the "Metro style" Start Screen and its associated full-screen tailored apps--and one that is old and tired--the classic Windows desktop and its voluminous collection of legacy Windows applications. You can move back and forth between these environments pretty easily--in some ways, the old Windows desktop is just an app, from the perspective of the Start Screen--and will in fact have to if you want to run even one classic Windows app.

This has been described as "jarring" by some and while Mr. Sinofsky may not agree, I do find it somewhat jarring. It's not a huge problem, and certainly not any worse than the experience Mac users had a decade ago switching between "Classic" Mac apps and newer OS X apps. In fact, it's better: Legacy Windows apps still run at full speed, of course, since this is not an emulation environment. But it's also something to be aware of.

Too, there is some confusion around the availability of ARM versions of Windows, which, unlike their more traditional x86/x64 brethren, will not be able to run classic/legacy Windows applications. So if you can name a single application that you download and/or install on Windows today, that app will not work on ARM versions of Windows. These versions of Windows--which Microsoft says will be clearly marked and labeled to avoid customer confusion--will only run a new generation of Metro-style tailored apps--which, yes, can be written in "real" programming languages like C++, C, C#, and Visual Basic in addition to HTML 5 (HTML + JavaScript + CSS)--that run in the tailored, full-screen, Start Screen.

But maybe I'm getting ahead of myself. Right now, what we've got is a pre-beta build of Windows 8, the so-called developer preview. It's not complete and is pretty buggy, but it does provide a very interesting glimpse of the future. So rather than focus on the negatives, let's instead step through some of the new features that are exposed in this product. And when you think about it in that light, two thoughts emerge: If you're a Windows Phone user, you already "get" Windows 8; it works, looks, and feels almost exactly like your smart phone. But for the majority of people who are not familiar with Windows Phone, Windows 8 is going to be pretty shocking. And that's OK. Because it's the good kind of shocking.

Windows 8 is pretty fricking cool.

Here's some of what's new.

Start experience. Windows 8 boots in under 10 seconds on virtually any kind of modern PC, and it's a wonder to behold. When you do reach the Lock screen (quickly), you're presented by a gorgeous, full-screen view that will be instantly recognizable to anyone using Windows Phone, complete with nice time, date, and notification elements.

Logon can occur via a number of methods, including via the tried and true password, but you can also use simpler methods that will make more sense on a highly mobile device like a slate tablet. These include a PIN style password (four characters) or the fun new Picture Password, which lets you utilize multi-touch gestures over a photo to logon. (For example, you could tap the photo subject's eyes and then swipe a smiley face. Cool.

You can also protect your Windows 8 PC with a new security scheme called Secure Boot that works with new UEFI-based BIOSes and prevents unprotected devices--like a USB key stocked with malware--from compromising the PC at bootup. Also, the system performs an early-load of anti-malware after the Secure Boot process validates, to protect things during boot.

Start screen. Microsoft debuted the Start screen earlier this year, so I won't waste much time re-describing it here. It works as expected, and as previously demonstrated, though there are some new bits. Unlike with Windows Phone, each tile on the Start screen is independently customizable, with two size choices (rectangular and square). Also unlike Windows Phone, the Start screen scrolls only horizontally (not vertically), and it works in either portrait or landscape mode. (Also Metro-style UIs do, another new find.)

The performance of this UI is astonishing, and it works really well even in this early version. Some of the interaction bits are interesting, since any superfluous UI is hidden until you need it. Unlike in Windows Phone, you don't typically tap and hold. Instead, you swipe down slightly on a tile to get its actions to appear on the bottom edge of the screen. Swipe in from the right edge of the screen and the Charm bar comes up. (Yes, the Charm bar.) It has five icons--Search, Share, Start, Devices, and Settings--and is available from the Start Screen or any full-screen app. (An overlay with the time, date, network, and power also appears when this view is open.)

The Start Screen also supports "semantic zoom" where you can pinch and "reverse pinch" two fingers on screen to zoom in (and out) of a tiny version of the full multi-screen Start Screen tile set so you can group tiles and optionally name the groups. It makes the folder management stuff on the iPad look as silly as it is.

Tailored apps. Jump into a Metro-style tailored app and you'll find a full-screen experience in which every single pixel on the screen is dedicated solely to that app. These are not "Metro" apps, as some have said, but rather "Metro-style" apps that are both immersive and tailored, according to the new Microsoft lingo. As with new Mac OS X Lion apps, these apps auto-save content and don't offer any explicit saving, and like Windows Phone apps, they are designed expecting to be killed at any time. (In reality they're suspended when you switch away from them and will stay like that until memory runs out or you bring it to the forefront again.)

Apps can also pan exactly like the Start Screen, which is neat, and they can offer semantic zoom as well. So in an app that offers news reading, for example, you could use semantic zoom (pinching) to change the view from an article list to a feeds list (or whatever).

As on Windows Phone--and yes, this is a theme--apps can also provide secondary tiles in addition to their standard live tiles. So in the aforementioned fictional news apps, you might decide to pin one of the news sources--CNN or Car & Driver, for example--to the Start Screen instead of (or in addition to) the full app. (This feature is also in Windows Phone 7.5.)

As demonstrated previously, you can Snap two Metro-style apps (or one Metro-style app and one classic app) on the desktop side-by-side. This requires a screen with at least 1366 pixels horizontally as I previously reported, and you can change the ratio of onscreen size that each app gets using a simple slider.

Built-in apps. Microsoft includes numerous built-in apps in the Windows 8 developer preview, though its unclear if they will be included in the final version. These apps will all written in HTML 5 by interns over the summer, which is Microsoft's way of saying they're very easy to write. Based on the code session we witnessed, that is certainly the case, and I'll be examining Windows 8 developer features in depth at a future date.

Internet Explorer 10. As Microsoft previously revealed, Windows 8 ships with IE 10, and in its tailored version it's a beautiful, full-screen app with no onscreen chrome. (A version of IE 10 is available in the classic desktop too; it currently looks exactly like Windows 7.) If you swipe up from the bottom of the screen (or down from the top), additional controls appear. These include a tab bar at the top (with a New InPrivate Browsing tab; a first) and an address bar and other controls at the bottom.

Contracts. As with OLE/COM back in the 1990s, Windows 8 provides a neat set of intra-application communications services that developers can harness so that their apps can interact with other apps and with the underlying system. Using this system, called contracts, two apps that know nothing about each other can work together implicitly to provide the user with a solution to a problem, much like two apps today can copy and paste content between them.

On such contract is the Share contract, which apps can register themselves with to become a sharing target. So let's say you're browsing the web and you'd like to share the current web page. You can swipe in from the right edge of the screen to bring up the Charm bar, choose Share, and then examine a new Share pane which contains a list of apps that can share content. These can include social networking apps for Facebook or Twitter or whatever, and as you use these apps in this fashion, they'll bubble to the top of the Share pane's Favorites group. Search is another contract.

Accessing the underlying PC. While the new Metro-style UI is designed to shield you from the complexity of the PC, the machine you're using is, after all, a PC, and sometimes it's valuable to access the many services and capabilities this device offers. You can do so through the classic Windows desktop, of course, and even that's being updated in interesting ways. But Microsoft also built useful extensions into its new tailored app platform that address common needs. The most obvious of these, and another Windows Phone feature, is the File picker. (In Windows Phone, pickers are called choosers.) This lets you interact with the files in the underlying PC file system--as well as those in various online services, which makes it much more powerful--so that you can arbitrarily select files that you want to act on (as when uploading them to a web site). Most interesting is that you can mix and match: You can select a few files from the PC, a few from one online service, and then a few more from a second online service, and act on all of them in a single batch operation. Very interesting.

Devices. Today, we attach printers, cameras, MP3 players, and any other number of devices to our PCs regularly through common ports like USB. In Windows 8, you can interact with devices through the new Devices charm, which provides access to printing, Play To, Send, and other options. There's a new version of Device Stage called Metro style device pack, which helps you access device properties inside of the Start screen environment.

And speaking of devices, Microsoft confirmed that this new UI is not touch-centric, but works well with keyboard and mouse or a Tablet PC-style stylus (complete with all the handwriting recognition and e-ink support and so on). There are a few small changes to the UI when you plug in the devices, and a few navigational differences, but everything works.

Cloud services. Remember when Microsoft removed all those applications and rebranded them as Windows Live and then started offering the package separately from Windows as something called Windows Live Essentials? Well, in the Windows 8 developer preview, most of those apps--Mail, Calendar, People (contacts), and Photos--are all available as free, full-screen, tailored apps. And as with so much else in this OS, they look and work much like they're Windows Phone equivalents. Which is to say they're beautiful and work very well indeed. There's also some interesting SkyDrive integration I'll be looking at more closely in the future.

Security. In Windows 8, Microsoft is finally adding anti-virus software directly to the OS, in the form of anti-virus capabilities in Windows Defender. (The startup program management feature that was removed from Windows 7's Defender is now found in Task Manager, another nice addition.) Windows 8 also adds the valuable SmartScreen filtering to Windows Explorer, so you can protect your PC from file-based attack not just from the web (the feature debuted in IE) but also from attached memory devices.

PC recovery. The Windows 8 recovery stuff is awesome and is going to represent a major milestone in PC reliability. There are two major options to note, PC Refresh and PC Reset. With Reset, you get a full reset, and the entire PC is wiped out and reinstalled from scratch. This process takes a few minutes currently and will return the PC to its factory condition; it doesn't require any external discs or USB key. With Refresh, your files, data, favorites, personalization, and metro style apps are all backed up, the OS is wiped out and replaced, and then everything is reapplied to the PC, leaving you with a pristine, running copy of Windows with everything (except for classic applications) exactly the way they were before. It currently takes 4 to 5 minutes.

OK, that's a lot of stuff. But it's only the tip of the iceberg. I'll be posting a variety of photo and screenshot galleries today and this week to accompany this article and will of course build out my Windows 8 content as we move forward. Consider the floodgates open.