I've worked with Unity 2 years ago, and i was planning on using it again.
But, when you google for it, you get to the microsoft site which says that the pages are no longer maintained, and another big hit is at codeplex.com.
At codeplex however, there hasn't been a release since begin 2010, and they promise movies in may/june (I assume they mean 2010) but they aren't there yet.
So I was wondering wether the product was still alive, or is MEF the new kid-that-rocks?
ps (bit offtopic)
don't know if i'm the only one but i never seem to get a good overview of the maturity / status / 'will they exist next year' etc. of a codeplex project, and the documentation most of the time is so-so