Microsoft finally surprised us all: At the eagerly-awaited first briefing for the next Windows, the firm revealed that they had decided to skip the 9 and call it Windows 10 instead. From a features perspective, we only learned about a few minor new features that hadn't already leaked. And as promised, the technical preview won't ship until October. Which starts tomorrow, by the way.

To say that this was a different kind of Windows event is a major understatement. I want to focus on the details of the announcement here, but it's at least worth pointing out that Terry Myerson's team is approaching Windows 10 with a completely different—for the better—approach. Not just when compared to the past few releases. But when compared to every Windows release from the past 20 years. Everything is new again.

OK, let's look at what was announced, what was said and what wasn't said.

We already knew (almost) everything. From a mile-high, if you've been reading along about the new Windows here on the SuperSite, you already know about virtually every feature that Microsoft revealed today. The name is new, of course, and Microsoft also showed off some new Snap-related functionality that was new to everyone. But that was almost literally it.

Why "Windows 10"? Windows 9 was the "natural" name for this release, Terry Myerson said, and was indeed the original name. But after joking about a few fake names—like Windows One—he noted that this isn't an incremental release. It's a major new Windows that will run on everything from headless Internet of Things devices to phones to tablets to PCs to the Xbox to the cloud. They really wanted to segregate it from current Windows versions.

One platform, not one user experience. Answering the obvious questions about scaling one system across such diverse platforms, Myerson was quick to point out that the platform was consistent but the user experience would vary. The same team—led by Joe Belfiore—is working on the Windows 10 user interfaces for phones, tablets and PCs, he said. It's a single product family with one store, and experiences that are tailored for each device. He called it "Microsoft's most comprehensive platform. Ever."

Why the enterprise focus? Today's event was short on end-user niceties and consumer features. Microsoft wants to focus instead on what is arguably its most important customer base and the one that was arguably the most disappointed by Windows 8: businesses and, more specifically, the biggest businesses that are collectively called the enterprise. Future milestones will focus on consumers (early 2015) and developers (April 2015).

Enterprise value. Windows 10 will focus on four key areas for the enterprise: It will provide a familiar, compatible and productive environment for upgraders. It will support modern management capabilities, including advanced MDM (Mobile Device Management) that works with all PCs and devices, not just smart phones and tablets. Enterprises will be able to customize the Windows Store for their users. And it will protect corporate data by separating personal and corporate data on all devices.

An upgrade for both Windows 7 and Windows 8. One of the more interesting aspects of Windows 10 is that it is designed as an obvious upgrade from both Windows 7 and Windows 8. In both cases, you should see what you expect to see. Windows 7 users will get a Start menu, taskbar and desktop. And Windows 8 users with touch devices will get a Start screen and updated versions of the touch interfaces they understand. But both will benefit from new advances, including the updated Universal app model that will now work right on the desktop.

Build number. The build of Windows 10 that Joe Belfiore demonstrated was 9841. Not sure yet if that is the same build as the Technical Preview.

Features we already knew about. Joe showed off the new Start menu, floating Universal app windows, Task View multitasking and multiple desktop access, and Task View access from ALT + TAB.

Minor new features. Snap has been updated with a Snap Assist UI that suggests apps to snap on the other side of the screen when you snap an app. Snap also supports tiled displays, not just side-by-side (which, ironically, looks like Windows 2.0). The command prompt is being updated to support universal keyboard commands and actions (like SHIFT selection and CTRL + C for Copy).

Changes to touch devices. In the Technical Preview, the Charms will still appear on touch-based devices, but that UI is going away. Microsoft will keep or adapt other touch UIs from Windows 8, too. Switcher is gone, for example, but when you swipe in from the left edge of the screen, you'll now see the new ALT + TAB interface, which actually makes plenty of sense.

Continuum: One major new feature. Of course, Microsoft still needs to address the problem of switching between the two interfaces that collided in Windows 8—the mobile environment formerly called Metro and the classic desktop interface—especially on 2-in-1 devices. For example, if you have a Surface Pro 3 and unplug the keyboard, should Windows still work the same way? A feature called Continuum, not available in the Technical Preview, will introduce tablet and keyboard modes that react on the fly depending on the hardware you're using. So we won't know for a while how well it works.

Windows Insider Program. To get the Windows Technical Preview, you need to sign up for the Windows Insider Program. It starts tomorrow, and the first version will offer upgrades for Windows 7/8.x users with x86-based PCs and tablets. In the future, other form factors will be supported too. But ARM is up in the air, and we weren't able to get a firm answer about whether ARM-based Surface devices and other devices will ever get the upgrade.

Schedule. The enterprise-focused Technical Preview starts tomorrow. In early 2015, Microsoft will ship a consumer-oriented milestone and detail new user experiences. In April 2015 at BUILD, the firm will reveal the Windows 10 developer story. And then Windows 10 will ship later in the 2015. How much later? I guess we'll have to wait and see.

Free? Rumors suggested that Windows 10 would be free to Windows 8 users, but Microsoft refused to discuss pricing, SKUs, or other things that will be decided closer to release.

More soon.