I don't think they will go all the way KZ2 either, but I think they may make the warzone similar to the warzone in KZ2, where there is gunfire and blasts all around, where you have to at times move forward as a team to push the enemy back.
I don't think Halo will go for cover mechanics or gun physics like KZ2, but i do think they will rank up the enemy A.I and notch up the intensity of the war.
Either way, I am very much dying to see more of Halo Reach.