Microsoft has launched it's own SQL Community site, which will be a one stop shop for our product teams, premier field engineers etc. to share their knowledge with IT Professionals. There's shed loads of good stuff here from training, to forums, articles and scripts.
I should just mention that this is not to be confused with the equally excellent UK SQL Community site run by MVP Tony Rogerson. This is the place to go for all the UK community events like the recent SQL Bits day as well as all the experience the UK MVPs have.