BUILD 2012 kicked off today, and Microsoft is finally rallying the Windows Phone troops. During their keynote address, the company announced the availability of the all-new Windows Phone 8 SDK which is now available for all to download. The lucky jerks folks who attended BUILD 2012 also received a nice treat: free developer phones from Nokia! (To watch all of the sessions from the event over the next few days, visit the Channel9 BUILD 2012 page.)

Anyway, the shiny new toys that developers can now tap into for the next-generation platform includes native C++ coding, in-app purchasing, the WinPRT APIs for common core porting to Windows 8, and more. Plus there are new hooks to leverage in some of the features announced yesterday like multi-size Live Tiles, Lenses, NFC, custom notifications, and custom lock screens.

Microsoft is pushing really hard to get developers and as a super-awesome bonus, they're slashing prices. Typically the annual fee to register as a developer is $99, no small fee by any means. But for the next 8 days, you can register for a one-year developer account for just $8. Yes, just cough up eight bucks and for the next year you can publish apps to the Windows Phone Store. Microsoft notes that if you do pull the trigger on this limited time offer, you will be charged $99 at first and in about 30-45 days you will be refunded the $91 difference. Still, points for being awesome Microsoft.

To register as a developer or download the new SDK, head on over to the newly-refreshed Windows Phone Dev Center now. (Or for a shortcut, visit the SDK download page here.)

Update: We wanted to note that the Windows Phone 8 SDK requires a copy of Windows 8 (64-bit) and at least 4 GB of RAM. Also the limited-time $8 developer offer may not be in effect just yet, so sit tight on that registration for now.

Source: Windows Phone Developer Blog, Dev Center