Re: bbPress MU
Sam mentioned a year or so ago that:
There will be a sort of super plugin that you will be able to integrate into bbPress to get most of the functionality of TalkPress. The working name for the project is “bbPress Channels”. It will be released after TalkPress.
TalkPress is their hosted “bbPress MU” – so it sounds like eventually, we’ll have the ability to host multiple bbPress sites from a single install.