Yeah, I have that video in my computer. At least Microsoft doesn't pull what I like to call the "Sony Killzone."
That E3 2006 video they showed of Halo 3 at the end of the Microsoft Press Conference was COMPLETELY real-time. Every bit of that trailer was processed using the Xbox 360.
To prove it, at the end of the conference, one of the Executive Producers (I think it was...) even used a Xbox 360 controller to move around the sun and the Master Chief to show off the dynamic lighting effects and everything.
I think it's coming out Q3 or Q4 of this year, so I can't wait. It'll be one of the games that will spur me to buy an Xbox 360.