Browsing MSDN this morning and saw the note that they now have Wiki support. If done well it could be tremendously powerful to get not just the official MS line but also the hard lessons learned that you often run across in forums and community generated articles. I haven't looked yet to see if they support adding new topics, it would definitely be limiting if we can only extend existing topics.
I'm Andy Warren, currently a SQL Server trainer with End to End Training. Over the past few years I've been a developer, DBA, and IT Director. I was one of the original founders of SQLServerCentral.com and helped grow that community from zero to about 300k members before deciding to move on to other ventures.