*wonders what he said*
I think it's good that you have a forum open to guests, I started posting as a guest, and being honest I wouldn't have even started posting if registration was forced.
On the flip side, you get idiots like above. You obviously have the power of IP banning, but then some people have dynamic IPs...
If you look at Joystiq.com's implementation of the comments system http://www.joystiq.com/entry/1234000777067882/#comments
, I think it's the best. If you want to post, you supply a username and email, and when you submit your message it will ask you to visit your inbox and click an activation link for the comment. This happens for everytime you want to post a comment.
P.S. Hurrah for the new version, good work!
Edit: Whoops, it's not a new version is it? So I withdraw my "Hurrah"