The newest version of WordPress is out, Version 1.5. They seem to have improved the commenting and moderation system, so I'm tempted to upgrade, because despite implementing my own captcha, I got bombed without about 30 spam comments last night. Thank god for "Mass Edit" mode...
I might try playing around with my captcha a little more, but I'm having a hard time believing someone actually figured out a way around my little captcha just to post comment spam on my little blog with an audience of about 2. Thus, I think they're exploiting a vulnerability within WordPress there and I may investigate that a little.
What bottom-feeders...:(