We’re not touching the bbPress standalone code any more. Any new forum stuff will be provided by bbPress plugin. Can the bbPress plugin do this? If so, you have your answer.
OK @djpaul, the answer is “NO”. The actual bbPress plugin has not this functionnality, but it exist a bbPress plugin who can do this: “support forums”.
The new question is now: is bbPress plugable when integrated into a BP multisite install ?
I can’t see why any plugins for the new bbPress plugin would not work when running on a site with BuddyPress. It’s plugins, all the way down