Pretty nice. I think Bungie got what they've deserved. They've been the little overlooked developers for way too long. All that work they've done since Marathon is finally paying off.
It's still neat to see how much of their old stuff builds into what we see here. Even when it comes to packaging (with the A.I. intercepts and message booklet) screams of the kind of communications Bungie always loved to do.
Of course, you don't make this kind of money with a first game in the series, so it does say wonders about the success of Halo 1.
Still, it's apparent (playing Halo 2) that Bungie wants even more power, in the future. They wanted to make it play with all the non-restrictions of a movie editor, so they did everything they could to make loading non-existant during the campaign. It does make for certain split-second pop ups at beginning of certain scenes (not there if you have a modified xbox with this on the HD), but it is still impressive how it can jump from one locale to a totally different locale, instantly. Whereas in Halo 1, you had a 10+ second load wait to accomplish the same thing.