The Asp.Net MVC framework has made some major headlines and rightfully so. It is a very very cool framework. I think it is definately worth a look, even if you never use it. I plan to be using it in the near future for some upcoming projects myself.
As many have said before me, it's not a replacement for web forms, so it's not going to be the best tool for every job. I stumbled across this blog post on whether or not you should use Asp.Net. It is well worth a read.
Should You Use ASP.NET MVC?