This may not be anything so sinister. This may just be part of a longer-term plan to phase out .net. We may eventually see it dumped onto either xamarin or a separate foundation, with it no longer getting any special attention from Microsoft. They can't do that all at once, it would piss of developers too much, but if they do it slowly, reducing its emphasis and chipping away bits and pieces, they may think they can get away with it.
No announcement yet.
So, Microsoft just open sourced most of .NET...