Mnemesis over at Bungie Sightings has posted his impressions from the Halo 2 demonstration at MS' E3 press conference. He seemed pretty impressed, especially with some of the new wrinkles the sequel is sporting:

Rounding a street corner, we get our first glimpse of the Brutes. They were pretty dark, but quite large and evidently strong. The MC got out of the Warthog to dispatch them, but a bunch of shots to the body didn't do anything, and a punch in the chest didn't either. Luckily, a well-placed grenade under a vehicle caused enough of an explosion to eliminate that particular threat, so the situation ended happily.

Then something miraculous happened. A couple of Ghosts were coming down the road towards us, and things looked pretty grim for the MC, when he jumped up onto the wing, and with one hand hanging on to the cowl, pushed the Covenant driver out and took his place! Man, that was incredible. I could watch that part over and over.

Be sure to check out his writeup.