A few months ago, there were rumors about online co-op, but no solid information. Just before Halo 3's release, the rumors were confirmed. After playing Halo 3 co-op on my LAN last night, I have to say that it doesn't disappoint.
Getting it to work is pretty simple—go into the Game Lobby, choose Campaign, and choose whether to use System Link or Xbox Live; there is the option of hosting a game or joining an existing one. Since we were in the same room, there was no need for us to use headsets last night, but I'll post more on this later after we try co-op on Xbox Live.
