No, absolutely, there are very cool things coming out of Microsoft with regards to C#/VC++. It's just that they nearly always come from Microsoft, there isn't an active community that does these things.
My point with the 3D body example is that it was not done by MS.
But take a look at a place like CodeProject. People post their projects and write up an article describing the technical aspects of that project. It's actually a surprisingly strong community. In the past month ~500 written or updated. I actually tend to find this place more interesting than GitHub or CodePlex, due to the exposition.
This can be misleading. Often these sorts of things are built by 3rd party companies and simply released by Microsoft or hosted on MSDN/codeplex or etc. A lot of them are just people at companies with pre-existing relationships with MS coming up with good ideas. It's not the same as more OSS-style ecosystems, but it's also not a centrally planned marketing facade, either.
