IRC works too.
However, the Ustream chat server is perpetual. You don't need a bot to hold the channel open. As long as someone has a registered show on Ustream, the channel is always available. (Even if you're not broadcasting at the time, the channel stays open.)
So the Event Page chat window will *always* work. (At least, unless Spec changes the event page or I delete my channel on Ustream... Neither of which is likely!)
I'm sitting in the channel right now. There's one other Ustream member in there, but he's not talking.
Remember to type /nick and then your name to change your ID. (Otherwise you'll be "ustreamer-675730" or something.)
Adam