I guess New SMB will not move as much hardware as FF 13 simply because Super Mario Fans bought a Wii while a lot of Final Fantasy Fans don`t. In the FF Fan Forums a lot of people are waiting just for that game.
Saturation is another point why the Wii wont start sell significantly more than the PS3.
I think PS3 will at least reach the goal in the same time Wii does but maybe quicker.