I had this hanging around for a while so I thought I may aswell publish it.
I tried quite a few import scripts to get my posts and comments from my old bBlog install over to my new WordPress 2.0.1 installation, but none of them worked properly.
I found one in php which worked for WordPress 1.5.2 and tweaked until it worked on 2.0.x series, it also imports some extra info like commentors IP addresses. (I suggest this one for 1.5.x)
It took me a long time to get it to update the comment count on WordPress properly.
Imports categories properly, simplified it and I straightened up the workflow a bit.
If you have a newer version of bBlog it should be pretty trivial to get it to work.
The original came from here:
So here you go, an easy to use and reliable bBlog to WordPress import script!
You can download my bBlog to WordPress 2.0 converter here.