The core of the problem is that Android has the lion's share of interested from handset makers. Since Android and WM7 are handset-agnostic, its obvious that manufacturers are going to go with whatever they feel will make their phone sell better.
Of course, Android came out sooner and has a lot more interest and advertising dollars behind it, so its going to do better. Nokia coming on board will be a very significant move in the right direction (probably to the tune of 15-20% market share by the time they make the switch).
The real question is if other manufacturers come on board in a big way or not. Nokia's smartphone market share has been dropping faster than a rock (relatively)....So Microsoft is buying into a weakening manufacturer.
I'm unsure if the overall move will let MS win in any way. Likely, it will make them more viable than say....RIM, but that is hardly an accomplishment now.
Back from the dead, I'm afraid.
