I don't want to come down on either side of a console war here but I believe that the above images clearly show why everyone should be playing Mega Man 9
on the Wii if they have that choice. You may site other benefits to other systems but they are all blown away by the fact that the Wii has the controller with the closest design to a classic NES controller. You're telling me you're going to play an entirely retro fitted game with a controller that has a analog pad on it? That's an insult to the game itself and the hard work that Capcom put into it. The game is meant to be experienced with a rectangular controller, with two buttons and a D-pad that doesn't have any webbing between its directions. Playing it on anything else is like making baby Jesus cry, and not just by making fun of him but by kicking him in his Christ balls. Not only are you kicking a baby in the balls, but it's baby Jesus. For shame.
Yes in this case the Wii's lack of suitable control options for regular gaming is a blessing, so don't shun it.