On Monday, Steve Ballmer made some interesting changes of leadership over at Microsoft. First up, leadership of the Windows Phone 7 team has been taken away from Andy Lees, who has been steering the WP7 ship for three years now.

Terry Myerson, vice president and lead engineer will take his place. Lees has been moved to yield "maximum impact" of Windows Phone 7 and Windows 8 in 2012. "Maximum impact" is not clearly defined, so we don't know what Microsoft are hinting at here. It could be tighter integration between Windows Phone 7 and Windows 8, which is something I'm sure Microsoft are aiming at.

In Ballmer's memo, he notes that Myerson played a key and highly successful role working with Lees by leading the engineering work on Windows Phone 7 and 7.5. Myerson is now in control of Windows Phone development, marketing, and other business functions.

Both of these changes, according to Ballmer, take place immediately.