I agree with Vagrant on the 360 buttons showing in the games. The best examples are Rainbow Six Vegas, Lost Planet, and Halo 2 for the PC. Though the buttons show up as keyboard buttons if you are using a keyboard and mouse, but yes, they do show 360 buttons when you have a 360 controller connected. I myself have one. I don't agree with the way Vagrant made his point however, but that's besides the point.
I have seen the Epic forums, Youtube, and now Wiichat. Epic and Youtube seem to be buzzing with discussion about this video, and everyone seems to have jumped to the conclusion that it is a pc port. I think more likely, it's just their beta testing an expansion / downloadable content for the 360 game, on pc.
I think it was last year, that the guy from Epic said that they run the engine on the pc to test it. This was when people discovered the GoW exe within the nVidia drivers.
I really do hope this is a pc port, but until we hear from Epic themselves, I'm going to consider this new 360 content being tested on the PC. But I guess we wont know until we know.
That live gamer bar is pretty interesting though.
I am still holding out for a Dead Rising port. I need a freeroam game that I can keep coming back to. Ah well, all things in time.