MSDN .Net framework site (http://msdn.microsoft.com/netframework) has a feed for .Net framework Featured blogs

http://msdn.microsoft.com/msdn-online/shared/components/rssaggregator.aspx?OPML=/netframework/community/clrblog.opml&link=http://msdn.microsoft.com/netframework&Title=.NET+Framework+Featured+Blogs&description=.NET+Framework+blog+entries+from+team+members

It is mostly blogs by people from CLR team.

Subscribe to the feed if you want to know more about CLR.