That is right, 4 players over the net (Xbox live or System Link) can cooperate on the “single player” game.
(There is also 2 player co-op split screen)
One player plays the Master Chief, the other 3 don’t
http://www.bungie.net/News/content.aspx?type=topnews&link=thesoundofsack
Brian
You! Disposable henchmen! On me!
Oh, yes.
Mmm, hot! Not enough games even have two player co-op.
Yum. And double yum. Two player co-op on 2 was fun enough. There shall be much friendly fire. 
Yes, but you can play this co-op, even with 4 people, over Live.
This is going to be very fun, but I get the feeling I’m going to be carrying a lot of the people that I play with on another message board.
That rocks.
I’m enjoying Rainbow 6 Vegas co-op right now, but Halo would be 10 times better.
At* least * ten times better.
I’ve never been a fan of the Halo series but this could get me into it. The co-op mode in Gears of War has been my favorite online experience with the Xbox thus far.
This reminds me, I never added any Doper friends the last time a Gamertag thread came up. If anyone would like to add me, my tag is Storm Ravynn.
My problems with Gears’ co-op is that it abruptly stops if someone witis out. The problem with Halo has always been the blue screen. If they handled changing hosts like Call of Duty 3, itd be that much better. That makes me believe there’s a reason its not like that to begin with.