Re: question about exporting from bbpress
I haven’t heard of an export from bbPress to WordPress, but I don’t imagine that someone couldn’t write one in a hurry if they understand both programs. If you already have posts in punbb, you could easily export those posts to phpbb format and then use the import from phpbb to bbPress.
If you already have your comments and posts in a forum, why not setup a new WordPress blog once you have all your posts imported into bbPress and then have all new posts in WordPress go to bbPress for comments and further discussion. That way, all your old posts are already in the forum and all new posts will end up there as well. This is easily done with the bbPress-Post plugin. All new wordpress articles are created in bbPress and a link is placed in the wordpress post to the corresponding bbPress post.
Just something to think about.