I think it will do pretty well overall, a bit above what X1 is selling.
It will do very well in Japan especially because of the portability of it .
But overall, I think the sheer weight of IP will make it do well. There should be no Wii U style droughts on this console, not with the amount of games Nintendo itself makes, not with the amount of Japanese 3DS support that will surely carry over and not with any deals Nintendo has made with other devs.
Having 3D Mario, 2D Mario, Mario Kart, Splatoon, Zelda, Pokemon, Fire Emblem, Pikmin, Animal Crossing etc all in one place will be very attractive to people I think.