Anyway, the only non-nintendo games that I know that have nintendo like legs are Gran Turismo, The Sims, Diablo and Starcraft(there should be others, but i only know those).
GOWII will have good legs,this game can reach 5 million or even more in the end of this gen. My guess is 3.5 million til 2010 ending and 5 million til 2012 ending.