I checked it out last night. Messed around with Zeus and Beta until they went to watch ultimate fighting.
I have to say, with just the 3 of us on it was mostly smooth. I'm on 56k, buy my ping stayed pretty much around 215, which is low for me. I never have a constant inloss/outloss, my connection saves everything up for the occasional 10-15second lagnap. I had 2 of those within 30secs of joining the server, then nothing for over 5mins, then nothing after that. Pretty cool.
As an aside, I think they were letting me win the fights.