Have Nokia actually committed to dumping MeeGo? It seems like if it achieves unexpected success there should be room to course correct.
For example, OS/2 was supposed to be Microsoft's future in the late 80s, and Windows was a stopgap. It wasn't even clear there would be a Windows 3.0 at all, until a couple of developers secretly took on the task of getting Windows running in protected mode (http://blogs.msdn.com/b/larryosterman/archive/2005/02/02/365...) .
No, they never said they would dump MeeGo. They said they would be dumping Symbian, and left MeeGo as a research project for "future disruption". Of course, they have stated to fully commit to Windows Phone.
Recently they have been backtracking a bit and promised to keep updating/supporting Symbian until 2016, but the plans for MeeGo are unclear. However, they have stated that they will continue providing OTA updates for the N9, but that doesn't really mean anything.
I'm sure they don't really know the place for MeeGo right now, especially with the pressure from MS and the current success of N9.
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.
For example, OS/2 was supposed to be Microsoft's future in the late 80s, and Windows was a stopgap. It wasn't even clear there would be a Windows 3.0 at all, until a couple of developers secretly took on the task of getting Windows running in protected mode (http://blogs.msdn.com/b/larryosterman/archive/2005/02/02/365...) .