I think this is a big reason why the Nokia deal is so important to Microsoft. In pretty much every aspect, it appears that Microsoft is ultimately trying to push Nokia+WinPhone as a product in and of itself, with little thought given to the OEMs. In my humble opinion, this is the right strategy. Microsoft can't (and doesn't want) to compete with Android directly, since they'd be going up against an entrenched and inexpensive foe with whom the carriers and OEMs already have a strong relationship. And after Windows's dominance in the 90s, they know exactly how futile competing against that can be.
But by betting heavily on Nokia, Microsoft has guaranteed themselves a partner who will build hardware specifically tailored to their OS (and vice versa) and who will never have to choose between putting marketing dollars behind Windows Phone or Android.
We are each entitled to our own opinion, but no one is entitled to his own facts. -- Patrick Moynihan