If NX is another traditional console and it follows the path of the N64, GC, and Wii U, then I expect NX will continue the downward trend and sell less than 10 million (it will probably will get discontinued due to stagnating console sales like the Dreamcast did). I think creating another Wii success at this point is going to be very difficult just because of tablets and smartphones.
If, however, the NX is a handheld that integrates quality of life concepts and and is unified with Nintendo's new mobile platform, I think it can sell extremely well (> 50 million). A handheld that has quality of life features that smartphones do not have could be a device that people would like to have alongside their smartphones (I'm just picturing how a donut-shaped LCD screen could be part of a device that fits over your wrist while jogging :) ).







