I don't think the game has a broad appeal. Also, the pc sales are likely to eat into the 360 sales.
Lastly, the game is being overshadowed by many great games being released in the last couple of months. Most recently being Battlefield BC 2 and FFXIII, both of which appeal to a much wider audience than ME 2 (though ffxiii is obviously heavily ps3 sided).
Sales will fizzle if they haven't already. It won't move too much from where it is imo.







