This past Monday, April 12th, Visual Studio 2010 was launched.  And on that same day, Microsoft also launched a new line of  mobile phone handsets, called Kin.  The two product launches are actually connected, but only by what they do not have in common, and what they commonly lack.

On the former point: VS 2010 had released to manufacturing a couple weeks prior to its launch.  The Kin phones, meanwhile are not yet available.  We don’t even know what they will cost.  (And I think cost will be a major factor in Kin’s success…I told ChannelWeb’s Yara Souza so in this article).

What do the two products both lack? Simple: Windows Mobile 6.x. For example, Kin seems to be based on the same platform as Windows Phone 7 (albeit a subset).  And VS 2010 does not support .NET Compact Framework development, which means no .NET development support for WinMo 6.x and earlier.

So I guess April 12th marks Windows Phone “clean slate day.”  If you want to develop for the old phone platform, you will need to use the old version of Visual Studio (i.e. 2008).  Luckily VS 2010 and 2008 can be installed side-by-side.  But I doubt that’s much consolation to developers who still target WinMo 6.5 and earlier.

Remember, WinMo isn’t just about the phone.  There are all sorts of non-telephony mobile devices, including ruggedized Pocket PC-style instruments, bar code readers and shop-floor-deployed units that don’t run Windows Phone 7 and couldn’t, even if they wanted to.

Where will developers in these markets go?  I would guess some will stick with WinMo 6.x and earlier, until Windows Phone 7 can handle their workloads, assuming that does indeed happen.  Others will likely go to Google’s Android platform.

For OEMs and developers who need a customizable mobile software stack, Android is turning out to be out-WinMo-ing WinMo.  As I wrote in this post, Google took Microsoft’s model (minus the licensing fees) and combined it with a modern SmartPhone feature set (rather than a late 90s/early oughts PDA paradigm), to great success.  You might say Google embraced and extended.

You might also say Microsoft shunned and withdrew.