After seeing the first look on Halo 4, I have to say it looks like it will play A LOT like Reach will. I saw sprinting, and personally I don't like the feature. Isn't this game based of the Reach engine, too? They should really make it of the Halo 3 engine. IMHO I don't think this game will be good. Halo 3 was awesome. If it aint' broken, why look to repair it?
Who am I to say anything, though. They could change anything at any time. We're still months away from release.