For some reason I'm not seeing a forum post about this over on the SRB2 forums... and I think something like this would be on the main SRB2 page as well, but it's not. If this is a private beta, you could get in a lot of trouble for releasing it... if I don't see a forum post within the next 48 hours, I'm pulling the links out of your post.
That said, if this is allowed... awesome.
EDIT: Okay, I see the SRB2 IRC channel name in the title bar in OpenGL mode, so I'm guessing it's public. Just had to be sure.