I don't think it's necessarily incoherent to keep both around as this might give them a way to more easily try out ideas without whatever overhead of having to

I don't think it's necessarily incoherent to keep both around as this might give them a way to more easily try out ideas without whatever overhead of having to fit into the MS platform. In the future there might be some degree of convergence, e.g. Microsoft will probably eventually open up the marketplace to native code (maybe at the same time they move to an NT Windows kernel) and Nokia could port Qt.