Community member Kim Parsell passed this along to me regarding a new WordPress MU Support forum that recently opened to the public. Andrea and her husband who run WPMUTutorials.com are the ones behind this new forum.
Anyone is free to register an account but to dive deeper into the forums, you’ll have to purchase a membership. Memberships cost 20$ for three months. Considering the breadth of knowledge that Andrea has regarding WordPress MU, this could be a drop in the bucket for those who have a tough time managing the software.