If anyone is interested,
here is 5 minutes of shaky cam footage from inside ComicCon. The systems being used are Alienware quad-core systems with an 8800 ultra running the game on medium detail. As an employee of Epic stated, this machine is overkill even for the highest detail setting. You will get better performance from a dual core than a quad core at this time. He also mentioned that a dual core system with a 7800 card will run the game at 60fps on medium detail.
I'm glad to finally see some awesome footage of straight deathmatch. It looks spectacular. I will be waiting anxiously for UT3 to hit the shelves in November.