I'm not denying any of these facts, but do the math. In order to beat SMB, it needs a other 7milion. 7mil is over 1/4 of the 33mil already sold. Mario Kart Wii launched 4years ago. This means it would need have enough legs to sell 1/4 of what it sold already sold in 4years. It cannot be done. I think it will sell a other 2 or 3mil tops for a total of 35/36mil. Wii game sales are plummeting extremely fast, MKW does'nt have enough time left to sell 7mil. In 2years (if not1) it's sales will be close to insignificant, no way it will sell 3mil a year before then.
I don't think the price has ever been a issue, with 1/3 or the Wii's market owning MK I doubt a price drop will do much of a difference, almost everyone who wanted the game already bought it.
As for the WiiU factor, expect a Mario KartU in the next couple of years (if not next year).
I see wat your saying, I dont think it'll beat it but i do see it gettin close to 40mil. It doesn't matter about the year its in. The fact alone that NSMB and MKDS is 6 and 7 years old is still selling over a mil. The 5th and 6th year for both selling millions of copies!!!!! MarioKart Wii will sell the next 3 holidays with a mil a piece. The legs even after MKU comes out will keep going. The price cut will absolutely help if cut down to $20-$30 while selling in holidays! Im hoping for 40mil but My guess would be 38mil. Trust me, It can happen, Its Mario