From gamasutra.com:

Microsoft on Friday made official the promotion of Don Mattrick to president of the company's Interactive Entertainment Business, following the formal retirement of 22-year Microsoft veteran Robbie Bach.

Mattrick, formerly *** of the Interactive Entertainment Business, will oversee consumer entertainment initiatives at Microsoft, including Xbox 360, Xbox Live, Kinect, Zune Music and Video, Mediaroom, PC and mobile entertainment.
Full Story: gamasutra.com