That's a valid concern, in my opinion. I don't know why, but even talented Microsoft developers I've spoken to have been woefully unaware of developments outside of the .Net/ASP sphere. It's almost as if innovations don't exist until they've been incorporated into the CLR. I've seen similar attitudes in Java developers, but it appears to be far worse in the .Net community.
That was, in fact, one of the reasons I chose to keep practicing other programming languages while I was employed by a .Net shop. I didn't want to end up "stuck" knowing only .Net like so many of my co-workers.