Every major carrier will be pushing Android phones in 2010. Unless Window Mobile 7 is revolutionary, MS is pretty pretty much dead in the phone OS race.
It would not surprise me to see MS buy RIM or another company to try to increase their market share, but Apple/Google will rule the mobile space in the next few years.
MS need to take a hint from Apple and combine their Zune/phone/embedded OS into one consistent platform with one common app store.
I am not sure why MS is still in the business of making PC peripherals.