Lets face it halo 2 was a complete let down. The game play didn't even compare to halo 1. The Arbiter was just annoying (you know it is true). The only real thing that saved it was the kick ass multiplayer (thank god).
From the looks of things i don't think that the single player will be any better on Halo 3. I'm not talking about story i mean the whole brute pack thing. It's gonna suck not killing elites or hunters (not sure if this is true or not). The game does look like it took a thankful step back to halo 1 with the assault rifle and etc.