Bungie recently updated their website with some screenshots and details on a new Halo 3 vehicle, the M274 Ultra-light All-terrain Vehicle, known to its friends as "The Mongoose."
Bungie even gives us some potential Mongoose-based strategies:
Example – Valhalla CTFLocated at each base station on Valhalla are two Mongoose units. In a typical encounter, both might be ignored initially while your team takes off on foot, through the Mancannon or even in a banshee. Ignoring them is a rookie mistake however, especially in objective-based scenarios. While attempting to capture say, an enemy flag, sending out two Mongoose riders with passengers can be a brilliant tactical move.
Just something to think about while you wait for the beta. And wait, and wait.
via CVG