In late June, I provided a lengthy, hands-on overview of the Windows Phone 7.5 (then codenamed Mango) Beta 2 release. Since then, Microsoft has provided developers with a release candidate (RC) build of the upcoming mobile OS and has shipped the RTM (release to manufacturing) version of the system off to its hardware maker and mobile carrier partners so that they can contribute their own code to the OS. This overview is based on the RC build, which Microsoft tells me is roughly identical to the RTM version. That is, there are no functional surprises coming. What we see in the RC is basically what we're going to get when Windows Phone 7.5 ships to existing customers this fall.

It's not a review. I'll save that for the final OS, and render some kind of verdict at that time. For now, what I'd like to focus on are the changes I see in Windows Phone 7.5, compared to Beta 2, and whether these changes are valuable. If you're not familiar with the Beta 2 release, please do refer to my earlier Beta 2 overview before proceeding.

Installation

While the install process won't be as convoluted for actual customers, Microsoft offers a lengthy, multi-step and confusing process for developers. But at least it's possible. You'll break your warranty upgrading now, and if you lose the precious backup of your original phone set up, Microsoft warns that you may never be able to upgrade or recover the phone again without returning it to your wireless carrier for a refurbishing first. So it's not for the faint of heart.

Given this, I don't recommend that average users pay the $99 fee to join the Windows Phone developer program and gain access to the 7.5 RC. I know you're tempted, all the more so because the updates we've seen so far this year have been few and far between. But seriously, this is for dedicated developers only, and if you rely on your phone for day to day use, installing the 7.5 RC isn't recommended at all.

OOBE

The Windows Phone 7.5 out of box experience (OOBE) hasn't changed too much since 7.0. There's a much-discussed new Windows Phone logo, which is square instead of circular (and uglier than the original, I think). But for the most part, the process is very familiar.

Disconcertingly, Microsoft changes your theme color to red on dark as part of the upgrade, which I don't like at all. Why it would make such a change, especially on phones where the user has explicitly made their own theme choice, is unclear. I'd like to see that changed before the final release.

Twitter integration

The biggest change in the Windows Phone 7.5 RC is the enabling of Twitter integration, which was missing in action in Beta 2. If you're familiar with the improved Facebook integration in WP 7.5, you'll immediately grok the theory behind Twitter integration. But because of differences in the way that Twitter interacts with outside applications, there are a few gotchas here you need to be aware of.

First, when you enable Twitter integration through the new Twitter account type in Email + Accounts Settings, Windows Phone hands you off to an external mobile web page at Twitter.com. This is consistent with how Twitter integrates with other applications, such as those you might install on Windows PCs, but it's a bit jarring and un-Windows-Phone-like. You also need to read this page carefully, as Twitter is not allowing the service to integrate with your phone, it's integrating the service with your Windows Live ID. This is an important distinction. So if you purchase a new Windows Phone down the road and signon with your Windows Live ID, Twitter will be enabled automatically and by default. This may not be what you want, so just understand what's happening here.

Second, where Facebook integration into the phone will make sense for many users, Twitter integration may not, depending on how you use these services. That's because anytime you check-in, post a message, or perform any other social networking activity through your Me tile--the typical way in which you'll access these services--Twitter is enabled by default. Why is this a problem? Well, you may be OK telling your buddies on Facebook that you're out for the night and at a particular location. But doing so over the global Twitter network may not be what you intend. And while I consider myself fairly sophisticated, I made this mistake on my very first check-in with the RC, posting to both Windows Live and Twitter as well as Facebook. Oops.

For many, of course, this type of deep integration is quite desirable. And in addition to the Me tile integration, you can access Twitter in other logical places throughout WP 7.5, including the camera and Pictures hub, where you can share photos over Twitter, the People hub, where your contacts' Twitter tweets are collected alongside other social networking posts, and so on. Basically anywhere a Share option appears, Twitter is there.

But as with Facebook, this integration is sometimes limited. For example, the Facebook integration bit lets you check-in easily enough, but if you want to check-in others, you'll need to install, configure and use the dedicated Facebook app, just like users of other smart phones. Likewise, in Twitter, typing "@" in a new post doesn't bring up a list of your contacts. And typing "#" doesn't bring up a list of hash tags. You're on your own, and will still need to install that dedicated app. This undercuts the usefulness of OS integration somewhat, I think.

Finally, there's no way to edit or change your Twitter account. Once it's configured, it's up and running and your only option is to delete the account and start over. You can't change your Twitter account name on the fly.

Local Scout

The new Local Scout feature was a highlight of Beta 2, but I felt it was very limited by being inside of the Bing apps, which is only generally accessible from the hardware Search button on the phone and thus not obvious for many users. (Local Scout was, and still is, also available from Bing Maps.) In the RC, this has been fixed, and nicely: Now, Local Scout is its own dedicated app, available from the Windows Phone Start screen by default. That's exactly the right way to do this. Now, users will find and use Local Scout. And though the service will no doubt improve over time--I've seen numerous entries for restaurants, in particular, that closed long ago--it's already a very valuable app.

localscout_icon_0

Internet Explorer 9

Microsoft has made a lot of noise about its IE 9 for Windows Phone 7.5, since this new browser is basically a port of the desktop application and includes all of the important bits, such as its web standards support (HTML 5, CSS, and so on) and performance, the latter of which even includes hardware acceleration. And that's great, but I keep waiting for IE 9 to start working with modern web services like Amazon Cloud Player. And it still doesn't work.

Don't take this the wrong way, of course. IE 9 is still a big improvement over the decidedly lackluster browser Microsoft saddled us with in 7.0. But just dropping IE 9 into Windows Phone 7.5 hasn't made magically enabled many services. And that hasn't changed in the RC.

(In a somewhat related note, blogger Manan Kakkar reports that WP 7.5 can stream music stored in Microsoft's SkyDrive service, though this feature is unsupported and apparently unintentional.)

Maps

I greatly prefer the look and feel of Bing Maps to Google Maps, and in the Windows Phone 7.5 RC, Microsoft has improved matters yet again with a better UI. Now a more obvious button (now called "Me") will navigate the map immediately to your current location (well, assuming your wireless connection complies), and there's an iPhone-like location circle that's more accurate the smaller it appears. You can add (and name) Favorite places to Maps, and pin other locations. Which is neat, but despite all the integration bits in WP, they're not tied to your Windows Live ID, they're specific to the device. Wa-waa-waaah.

Moving on...

And that's about it. Frankly, the delta between Beta 2 and RC isn't that great, at least not on the surface. And that's just fine: Windows Phone is already a stable and mature OS, and the RC brings us one step closer to the final version of our first major update. I don't think that Windows Mobile 7.5 is going to change things dramatically, but it will keep Microsoft one step closer of its faster moving competition, and of course new hardware devices--especially the eagerly-awaited Nokia Sea-Ray with its vastly superior camera hardware--will make an even bigger difference. If you've bet on Windows Phone, Mango is nothing but good news. If you're on the fence, stay tuned for my review. I'm hoping you'll join me with what I feel is the best smart phone platform there is.