In busy forums, moderation can be a useful tool for gently enforcing good behavior. Drupal is pretty flexible in its support for moderation, but it could go farther to make moderation more effective.
Linking vocabularies to specific content types (page, story, project etc) is great, and what I think is one of the best features of drupal. However, there are definitely elements of this implementation that could be improved.
I'm curious how much work/how feasible it would be to extend Drupal to have a more flexible based group permissions system. I understand that you can setup "user roles" and assign a user a role, then define that roles permissions.