No one knows yet, we only saw a small teaser, the only people that would know are the guys at 343Nobody knows yet, but it might.
I want a Fightfire mode. I wanna be a firefighter! JK... JK... I don't know if there is, but we can speculate that it will. After all, the two previous Halo games have. But, 343 is making Halo 4, instead of Bungie, so they might not feel that they have to do it.
It has been said that the flood will be in it