There is a new video on gametrailers.com which is a documentary on the Brute which is pretty good. Near the end they show the new brute model, along with animation and textures as well as in-game usage of them. Judging by the Brutes themselves it appears that what you are really getting to see is just the new Brutes, the levels they are playing in seem to be unfinished graphically, with just placeholder art and effects. With the game still in Alpha, that makes sense. So just looking at the new brutes, Halo 3 is looking a LOT better. They show you the Halo 2 brutes and the beginning of the video, and there is quite a contrast.