As you might have already noticed, I integrated BBPress with WordPress, right here. It was not easy, nor straightforward, unlike folks around the web might have had you believe it.
I will open a discussion in my forum about this, as I will post an article describing what I had to do to make it work. In the end, it was all about lack of clear and updated information on the part of those bbpress blokes, but I finally found out that you should not try to integrate the latest WordPress with BBPress ’cause of cookies integration. It was simple, after all and I had to downgrade my WP version to 2.5.1 and all was well and yes, straightforward from then on. What wasn’t simple was to find out about it!…
My project involves a lot of customization of BBPress and I will make it public domain here. My code and such will be published under some shareable license as well.
Cya around 