Yeah, that is was I figured. The good xbox people will hang with the PC players but the good PC players will dominate.
I read something about the controller having somewhat better auto-aim compared to the mouse/keyboard setup. I think it was on cn3t review of the game. Here is what is said:
"This creates some really weird and potentially unbalanced trade-offs in multiplayer. By default, a player with a mouse will be able to turn more quickly and, if that player is skilled, more accurately than a gamepad user. Gamepad players can increase the right-stick sensitivity to turn faster, but they also get another benefit that feels downright dirty. Like the console version, the PC game employs a certain amount of auto-aim when you're using a gamepad. This makes sticking to other players for up-close shotgun blasts or melee attacks significantly easier with the gamepad, and there doesn't appear to be any way to disable it or even detect that another player is using a pad. After pumping up the gamepad's sensitivity, we found ourselves doing more damage when armed with a gamepad, which makes the two control schemes feel unbalanced, is sort of crazy when you consider how tournament-focused the current Halo 2 Xbox scene is these days."
Edit: Added quote from cn3t