Mattrick's exit from Microsoft reportedly due to impending executive shuffle

Bloomberg sources suggest detailed plans of at least one possible version of the future, putting current Windows leader Julie Larson-Green at the head of hardware engineering for the company. That shift would also give Windows Phone corporate VP Terry Myerson more control over the Windows OS across platforms, and Skype president Tony Bates the lead in acquisitions and developer relations.
Mattrick's exit from Microsoft reportedly due to impending executive shuffle

Some people have said that Windows Phone does Metro better than Windows 8 does. And Terry Myerson surprisingly has been able to get certain apps to come to Windows Phone that aren't in Windows 8.

And that could be viewed as a demotion for Larson-Green. Mattrick supposedly left because he wanted more than hardware engineering.