If that really is in-game engine material, that looks pretty awesome for what is a 7 year old console!
Always loved the halo series - so can't wait for this to come out.
ANY console of the current gen can do images that detailed if it's just a single character on screen I'd also like to point out that these aren't Xbox shots at all. They're 1600x900 renders. Regardless of the source, this will never be displayed on the Xbox. The Xbox version will run at a MAX of 720 pixels tall. In fact, my bets are that it will run at less, and be upscaled by the machine.
Plus ... I dunno, these images are just really really boring.