The Xbox version of Doom III currently in development at Vicarious Visions will feature co-operative online play via Xbox Live, according to word coming out of an Activision press event in California today. Our source on the scene reports that it "looks great" up and running, and that the four-player Live deathmatch mode is also quite something to behold.
Last month, Vicarious Visions CEO Karthik Bala revealed that two-player co-operative play would be one of the major additions to the Xbox version, but despite describing the game as "a showcase title for Xbox Live," the expectation was that co-operative play would be limited to split-screen and System Link options.

Interestingly, the co-operative mode - one of the most enjoyable aspects of the original Doom games - is something entirely of Vicarious Visions' design, and will not be appearing in the flagship PC version of the game in development at Id Software.