A year ago, I described the initial release of Windows Phone as a game changer and noted that I'd be using Windows Phone as my sole/primary smart phone platform going forward. I did this not because I had to, but because I prefer Windows Phone to the iPhone and Android competition. And sure enough, I've been using Windows Phone as my daily use handset since Microsoft loaned me the first pre-release prototype in mid-2010. And I've never looked back: As far as I'm concerned, Windows Phone is the most useful, usable, and innovative smart phone on the market.

Alas, I'm in a fairly tiny minority when it comes to making this choice. Depending on which market researchers you choose to believe, Windows Phone constitutes anywhere from 1 to 2 percent of worldwide smart phone usage, a figure that can only be described as disappointing. There are external reasons for this slow start--not the least of which are wireless carrier employee preferences for Android phones, which are updated with new features at a much faster clip than are other smart phones--but let's just suck it up and admit this is suboptimal and needs to improve.

Also problematic is the rate at which Microsoft updated the initial Windows Phone software over the past year, and the slow speed at which its hardware and wireless carrier partners OK'd those updates, allowing them to actually reach users' phones. Microsoft only delivered a handful of mostly small updates, a far cry from the performance of market leader Apple, which regularly supplies users of its iPhones with new functionality and bug fixes.

And then there's the hardware, which has been slow to rollout across carriers, with Verizon in particular not getting their first and only Windows Phone model until 9 months after the platform initially shipped. None of the first generation Windows Phone handsets--none of them--has a decent camera, and even my favorite Windows Phone, the Samsung Focus I've been using since last October, has other annoyances, including overly-sensitive capacitive hardware buttons that inadvertently trigger the Bing app at the worst possible moments. Some of the Windows Phone handsets are very good, yes. But none are great.

For Windows Phone enthusiasts such as myself, the last year, then, hasn't exactly been the victory lap we were hoping for. Yes, analysts from IDC and Gartner have somehow come to the conclusion that Windows Phone will magically leap past the iPhone by 2015 and achieve a number two finish behind Android. And yes, Microsoft has claimed that these predictions validate its phone strategy, but come on. That's a fantasy. The reality of Windows Phone's first year in market has been almost universally disappointing.

Except for one thing.

Windows Phone is still the most useful, usable, and innovative smart phone platform available. It's still nicer than the old-fashioned "whack a mole" iPhone user interface, which forces you to jump in and out of individual apps over and over again, like we used to do in MS-DOS. And don't get me started on Android: Google hasn't found an interface that's not worth stealing, and Android is a patchwork of inconsistent yet vaguely familiar user interfaces. It makes me feel dirty just using it.

And let's face it, webOS is dead. So is Symbian, not that that OS ever mattered in the US anyway. RIM's Blackberry is clearly on the downward end of its sales curve, a victim of corporate hubris, and even Verizon Wireless' CEO, no Windows Phone fan, has publicly stated that Windows Phone would beat Blackberry to establish itself as the third mobile ecosystem alongside iOS (Apple) and Android.

So it's not all bad. And looking ahead to Windows Phone 7.5, the first major update to Microsoft's fledgling mobile OS, things are only getting better. Much better.

Introducing Windows Phone 7.5

Codenamed "Mango," Windows Phone 7.5 is a free upgrade for all existing Windows Phone handsets and will of course be included on new handsets from numerous hardware makers. Conceptually, WP 7.5 isn't hugely different from its predecessor--indeed, the internal version number is actually 7.1, hinting at the lack of deep architectural changes--but that's actually a good thing. See, Microsoft got the basics right with Windows Phone 7, the first release. The foundation is solid. So this time around, it's all about filling in the missing features, the little nooks and crannies that occasionally made v1 a bit annoying.

(On a side note, I've been amused to read reviews from various tech reviewers and bloggers stating that, with Windows Phone 7.5, Microsoft has finally "gotten it right." As if this release were somehow a big departure and that by suddenly heaping accolades on the new version, we'll ignore the fact that these people all described the initial release as an also-ran a year ago. Folks, nothing major has changed in WP 7.5. This is evolution at its finest, and if you didn't like the first release, I'm not even sure what to make of you.)

In many ways, then, Windows Phone 7.5 is to Windows Phone 7 as Windows 7 was to Vista: The same basic OS, but streamlined, spit-shined, and made better. While there are a few big box changes, most of the many new features in this release are small tweaks to existing features. But these little changes really add up. They're everywhere. One gets the idea that Microsoft would have shipped this as the first release of Windows Phone if it only had the luxury of time.

So where the initial release of Windows Phone was about "reimagining the phone" with a "smart design" that "puts the user front and center" so they can "focus more on life and less on the phone," Windows Phone 7.5 is about "completing the vision." The core mantra is the same as before, it's just been improved across the board, and then some. Windows Phone 7 was already the superior smart phone platform. But now Windows Phone 7.5 is even better.

Of course, Microsoft's competition isn't sitting still either. Apple has already introduced its first Windows Phone-like features by building Twitter integration and one-click camera access into iOS 5 and you can expect more of that in the future. And I'll try not cringe while Android's army of copy-catters pillages Windows Phone feature by feature. There's a reason these better selling platforms are aping the supposedly inept Windows Phone: Their makers know that Windows Phone really is better.

OK, let's see what's new in Windows Phone 7.5. In the next part of this review, I examine the handful of big new features.