official site for Halo: Reach. The trailer, posted after the jump, features footage both old and new, blended together to tell the stories of a handful of Reach inhabitants who are struggling with the decision between "fight" and "flight" in the month preceding the events of the game.
Check out the super dramatic vignette below. Also, a word of advice to the poor souls therein: Flight, you guys. Seriously, skedaddle. You do not want to be on that planet during the next few weeks.