Mario Kart Wii is going to end at somewhere around 20-25M (breaking 30M seems impossible, but I thought that about breaking 20M too in August...)
Ps3 is likely to sell at least 45M.
Mario Kart Wii has very little chance of beating the Ps3. I don't think Wii Fit has much of a chance either really.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS