2015 will be WiiU's biggest year on the backs of 2014's big titles, a steadier stream of new quality releases, and a lower price, and maybe some unexpectedly good things from amiibo or something.
2016 has no shot at being above 2015, the console is simply too niche and old and there will be no titles that can push like MK and SSB. It will continue to decline from that point until discontinuation.
I'd be glad to see that 20 million some mention. Quite happy, actually.












