Well Microsoft officially announced it’s Mobile 7 platform last week and it has generated a lot of buzz. You can find out more about it at http://www.windowsphone7series.com/.
Shortly after that, MIX announced that there will be a dedicated Mobile app/game track. You can watch an interview with Charlie Kindel on the Countdown to MIX here : http://channel9.msdn.com/posts/LarryLarsen/Countdown-to-MIX10-Charlie-Kindel-and-Windows-Phone-7-Series/
Remember if you can?t make it to MIX, the MIX team is incredible about posting the sessions on the MIX Website. If you do plan to make it out to MIX, I hope to see you there.