Terry Myerson, Corporate VP of Windows Phone Division, welcomed Gruhler to Microsoft, stating:
Windows Phone has seen some minor shake-ups the last six months, but most of the movement has been within Microsoft, rather than departures. Gruhler’s predecessor Achim Berg, for example, has moved on to VP of of operator channels, where he will focus on collaborating with network carriers, media companies, and other channel partners.
It does seem as though Windows Phone is in need of a fresh marketing take. The "Smoked by Windows" campaign was fun for a while. And Nokia’s Amazing Everyday campaign has thrust them to the top of WP7 vendors, but even in the best major markets WP7’s market share is just over 3%; with the amount of money that Microsoft is throwing at Windows Phone advertising they probably expect a higher return on their investment.
source: 4-traders via WMPoweruser