I expect the brutes to regenerate health like the spartans and elites are able to regnerate their health and shields. though Bungie for the most part have been good in keeping their secrets, I remember one update from their site stated And the MLG boys will sweat blood with excitement. They will all still moan at me about how we nerfed the pistol from Halo One, but this new thing will at least cheer 'em up for a few months. Or years. It's that big.
makes me wonder if their is some new gameplay added on, or hell maybe in campaign we actually fight alonside Linda, Fred, and Kelly and in co-op take control of them ala Gears of War.