Well, now that you have got quite a few new features added, and quite a few bugs fixed, I beleive a few things are needed to transition from b2 to WordPress.
Go through and change the filenames to wp, rather than the current name of b2. To have half the files named b2, and the other half named wp seems weird to me. This would include directory names.
Also, it would be nice to have some better documentation. For those of us that don't want to use the default index, how about a list of the php variables, what they represent, and how to use them? Also, a better readme, with better installation instructions is severely needed. It will help keep support requests down a little.
Also, how about some buttons? Like the "powered by b2" button. I would like the default 88x131.
I would like to see all of this by the time the next major version comes out.