Bungie's Luke Smith has confirmed what everyone has been waiting to hear: Halo 3 will indeed support four-player co-op, either online over Xbox Live or via System Link.
One player will control Master Chief, another will control the Arbiter, while players three and four can take control of two new Elite characters - N'tho 'Sraom and Usze 'Taham, respectively. Is it just me or has your Halo 3 excitement jumped through the roof?
The Tru7h About Co-Op in Halo 3 [Bungie]