I've been considering a forum plugin for my WordPress site. So far, Mingle forum is the best out there. I'd like to see a faster release cycle, and a cleaner theme. Without images, I say.
Also, I'd like the SEO module NOT TO add the forum ID after the pretty name.
e.g. "forum/butterfly-merchant-group3/general-forum8/just-wanted-to-say-thanks-thread16/" - I don't want to have the "3", "8" and "16" there.
Also, cartpauj, you'll have serious competition the moment bbpress is launched as a plugin.
I insist with the "no images" appearance. CSS can do all that, even better.
Good luck with your hosting!