Well all the buzz is about the premier of Halo Reach, but what about the spin off's that 343 Industries will be doing? I know that those will be a little later on, but think of the possibilities for games. Contact Harvest, where you play as either A. Sargent Johnson, or B. a marine that was their at the time. Oynx playing as a Spartan III, battling the covenant all over the galaxy. Not to mention the Covie spin off's, Maybe a grunt one? playing as a grunt would change the way the game plays for sure. Also more elite spin offs. Maybe one based soley on the Brute vs. Elite war.
Maybe they just shouldn't make any more Halo games. I think we've had enough, it's just getting milked at this point... but, if they're going to make more anyway, well, I think that the Elite/Prophet War that started the Covenant in the first place would be an interesting story. Or even a game that shows what the Elites do after the Arbiter leaves Earth in Halo 3.
Of course we need new Halo games. Halo must not die. You hear me ultra-awsome super-spectacular halo game series!!! Do not quit now, or you will never achieve immortality!!! But overall, multiplayer is really what keeps games alive. As long as bungie can keep a good story-line, and give players a new experience, Halo will keep chugin' along like the juggernaut you know it is.
Well it won't be bungie, unless they go back on their word. Halo Reach is Bungie's last halo. But 343 will take over and have planned 6 more years of halo/halo inspired games.