This did not work for me. In fact, it was the thing that hindered my integration from working properly. That is just my experience, though.
Following these instructions:
http://bavatuesdays.com/integrating-wpmu-buddypress-and-bbpress/
I finally have WPMU-bbPress integration working.
There are several tips and an additional plugin mentioned there that are essential with WPMU integration.
Sam’s screencast helped with everything else.
