I'm still shocked Microsoft couldn't get its act together and stick it out with their mobile platform. One of the main things which absolutely killed their platform was how they handled their app store. Had they managed it better by making it easier to build apps for their platform like Android has, they would've been able to stick around longer.
Shame really and makes other players hesitant to come into an industry when you have a behemoth like Microsoft fail so badly.
December 10th of this year was their sunset date for support.