Not really in topic, but M$ and bungie can't afford halo 3 to be a more of the same (or slightly better) like halo 2. That would probably kill the franchise.
Back when halo 1 was released it represented some important evolution of the genre in a few ways and it instantly became a classic and a relevant title in videogames history; but the concept stayed exacly the same for halo 2, execution was only marginally better overall and the gameplay started to feel a little too simple.
Now, bungie *needs* to think of something new, something that will make people say "wow, no one has done this before / that's something that just wasn't possible on previous generation consoles (and i'm not talking graphically)".
Either they go *utterly crazy* on graphics, and i mean GOW levels or above, i mean something absolutely astonishing, or they need to think of some revolutionary new feature; i personally hope there's something more to gameplay than shooting this time around. It worked for halo1, kind of worked in 2 but it just won't be enough for halo 3, however well executed, imho.
A similar approach to that used for halo 2 would kill a lot of people's interest in the franchise, i think.