It's often a good idea to keep an eye on the competition, and Merkinjata has informed us of a major Tribes 2 preview-interview at Planet Starsiege. Tribes 2 is currently scheduled to ship this Summer and is expected to be one of the prime competitors for the multiplayer game in Halo.
You may note a certain convergence between some items on Tribes 2's promised features list and the information which we've had on Halo for awhile. How much of this was already planned out before Halo went public is anyone's guess, but it'll be very interesting to see how these two games stack up against one another. It shouldn't be hard to guess which one I'm betting on. ;-)