I thought you might want to take a look at this blog posting - Launched: Social Bookmarking V1 on MSDN and TechNet - although I haven't had the leisure to explore it yet myself.
The stated goal is: "These new sites, which have been available in preview since May 2008, make it easy for Microsoft's enormous technical community to help each other discover the best resources on any topic from across the web."
The documentation team is frequently and painfully reminded that discoverability of content is as much or more of an than quality!
-Doug