How is this even a question? Mario Kart 7, Pokemon X/Y, and NSMB2 guarantee the 3DS at least two.
Mario Kart 8 and the possibility of Wii Play U/Wii Fit U will give the Wii U at least one 15 Million seller.

There are sure to be more on the 3DS, as well.

The only thing that is definite is that the PSV won't be touching that 15 Million number.

Modern Warfare 3 on just the xbox 360 passed Pokemon Black and White and is about to hit 15mil. CoD certainly stands a chance. Especially if sales don't get evenly split between two consoles like they did this gen. Some 3ds games are selling better than their DS counterparts, some are selling worse. So it is not guaranteed that x and y will pass 15mil. Would be nice if both of these heavily milked franchises lost some steam next gen though.

Anyway it will be mostly nintendo games, because microsoft and sony don't have any big IPs left and the big third party ips get split between multiple systems. 

pokemon x/y should do over 15mil easy, its one of the most hype gens since the first 2, not saying its gonna beat gold/silver sales but its definetly going to surpass black/white sales. i mean people that skiped 5th gen and/or 3rd/4th gen is coming back for x/y! Also we'll get pokemon Z in 2015 and that will do 7mil+ and then follow up with sapphire/ruby remakes in 2016 with 9mil+ sales

Oh in that case that is probably only possible on the 3DS.