Stumbled upon this except from a Macweek article on Halo:

New York -- During Wednesday's keynote presentation at Macworld Expo here, Apple interim CEO Steve Jobs offered Mac gamers a sneak peak at what may be one of the most successful games of all time: Bungie Software Products Corp.'s Halo, a third-person-perspective, multiplayer game that allows up to 32 players -- 16 per team -- to engage in vicious head-to-head battle across networks and Bungie's own Internet gaming service, Bungie.net.

This is, of course, unconfirmed right now... but entirely possible. And will it be enough to be both ground breaking and satisfying?