I seriously doubt WM will vanish unless they somehow horribly fumble with WM7. I mean, did Windows go down after Vista? Has the Zune died? No, they came out with Windows 7 and the Zune HD. Xbox360 is doing pretty well, too. All indications are that Microsoft has finally woken up and sees that they can't just kick back and enjoy the monopoly anymore.
And I think everyone is getting the numbers wrong, too. At least in the US, WM only recently was surpassed by iPhone. So it dropped from #2 to #3, with RIM at the top. That means more Wm than Android or Palm. If there's anyone in jeopardy here it's Palm, as some think they're in trouble.
http://www.engadget.com/2009/12/17/c...he-first-time/
http://wmpoweruser.com/?p=12391