hes kind of right, all they can really add is characters, tracks and on-line. Although wi-fi was allready in the DS version. They upped the graphics a bit and added jumps, bikes and a trick system. Thats pretty much it.
maybe its because the series allready has a huge fan-base. Alot of people would buy this even if the changes were extreemly minimal. Because this is a mario kart game, and everyone apparently loves it.
Basicly if you put the words Mario, Zelda, Metroid Prime, Smash Brothers or F-Zero in a title on a Nintendo system, the unwashed masses will still flock to the store and buy every unit their under paid scabs can produce. Simply because of the title on the case.