I know WM isn't exactly gold now, but MS is big and committed and if a partnership is reached WM could be tuned to the hardware pretty well.
If anything, Nokia needs to establish a relationship with an OS that is young and malleable and backed by a large company. Intel's solution isn't a bad choice, but it may or may not work well. Having a backup is far from bad from any standpoint.
And frankly, WM might kinda suck now but it's too young to call and, if history has taught us anything (by us I mean Windows developers) is that MS work is well documented, with examples and a huge user base.
I know I'm preaching to a select OSS crowd but it's not so bad, really, from developer and user standpoint. Not too good if you look to admin a Linux machine, though.
On the good side, actual navigation.
Oh, and, they aren't doing damage to MeeGo. People who make the distinction from Linux to Windows will have a choice and those who don't would have bought anyway. They'll see how it goes and favor the winner. It's bad business to put all your eggs in one OS.
I, for one, welcome out new MS overlords.