By jan 1.
Ps4: over 15m no questions asked.
Wii U: can get to 11. with the diversity of games coming this holliday I see 10m easy. Even if the games coming to it are not system sellers, there are no games of thouse genres on either ps4 or x1, so fans of thouse types of games will have to get a wii u. Bayoneta, captain toad, hyrule warriors, sonic, smash will add up to be the best system seller dwarfing any combination of third partys coming this year since they are all very similar and already have existing games of the type, so nothing new.
X1: will not reach 9m. since multyplats wont sell the x1 they will just sell software to existing owners and they have no must have exclusives, they will be lucky if they pass 8m. Sunset overdrive and MCC will only apeal to already existing owners because since the anouncement of the console thouse games where anounced or rumored so people where expecting and bought the console in anticipation.