Re: phpbb3 -> bbpress converter
No, but I wouldn’t recommend using more recent builds of bbPress… since a lot of plugins aren’t supported in 1.0 yet. Unless of course, you don’t plan on using many plugins… then ymmv.
You can get user integration (complete with cookie support) between just about any two versions of bbPress and WordPress. Start a new thread with your questions around that, and we can all chip in and advise!