Epic is certainly getting close to finishing Unreal Tournament 3, since Mark Rein commented on the Epic forums that "The development team feels they're pretty close to being ready to release this so it could come out this week but for safety sake I'd say it should be out within two weeks."
According to that same post, mentioned PC beta demo will feature standard online mulitplayer, as well as the single player instant action mode to enjoy the bot AI. The purpose of this beta demo is to test the game on various hardware configurations and to get additional feedback from the community.
We are getting close and Mark Rein's November release plan just might be true.