I just came across this very un-Microsoft looking Microsoft webiste for SQL Server. There are a number of videos here geared towards different audiences. I haven’t watched them all, but I did find Scott Konersmann’s video about upgrading to SQL 2008 very interesting. And some of the For Fun videos are pretty funny – especially “It is invisible”.
Update on 3/2/2011 – Looks like the links I originally had are no longer working. I updated the links that I could find.