Interesting idea about buying smartphone market share, but if I were MS I would rather own RIM's Blackberry market. It has 43% of the smartphone market and it's verging on a monopoly of the corporate smartphone market at 70%. The corporate Blackberry audience seems like a good fit for MS's services and apps. MS has shown that they are good at leveraging a monopoly to crush competition.

RIM would be much more expensive than Palm, but, despite recent gains, Palm feels like a dying brand. And it seems like it would be near impossible for Palm to convert all those Crackberry addicts, especially since corporations hate changing to a new platform.

For small businesses that run an Exchange server, WinMo is a better option than the balckberry since you need to buy extra equipment to sync the blackberry with a Exchange server. On the other hand, the choice of WinMo over RIM costs little-to-no money.

However, I don't see why MS would want to buy a hardware company. I think they have their hands full with the xbox and zune.