The BlenderQA site was recently pointed out to me (a Designerly.net site using the Question2Answer system). It appears to have been in operation for 10 months (oldest question is 10 months old), though it has less than 100 users.
For discussion: Would starting a Q&A site under the StackExchange banner help drive more community there, or should those who want a Blender-specific Q&A site simply use that existing community?
Proposal: Blender