I wouldn't be so quick to discount this move. It could be a classic Microsoft embrace/extend/extinguish move. They lost the first round on mobile phone platforms, but this would allow them to very quickly create a platform that has developer support - after all, porting your apps from standard Android to an AOSP fork is easier than than porting it to Windows Phone. Especially as Microsoft/Nokia is pretty much the only organisation on the planet at the moment apart from Google and Apple that is capable of offering all of the same services that stock Android provides, making porting even easier for app developers.
The latest Android look and feel is not so different from Windows Phone either, once you actually get into the app. You could imagine a "Windows Phone" homescreen skin with Android Apps behind it, and it would be really quite a decent merger of the two environments, graphically speaking.
If they throw a bit of money around to encourage developers to undertake the (hopefully) relatively simple task of porting from stock Android, it's not impossible that they manage to get a pretty decent App Store together, which would solve the app problem for the otherwise fantastic Nokia hardware that they have been making these last few years.
Anyway, there's a lot of conditionals in the stuff that I've just written, none of it may come to pass, I'm just saying that it would be unwise to dismiss this effort without at least waiting a bit to see how it pans out.