Statistically, hardware with a main seres Pokemon game skyrockets into year round success. The 3DS showed similar patterns that the Wii U did (suffered awful sales, confusing name, gimmicky concept that made the device suffer from very meh specs), then X and Y were released and the thing exploded (and sadly killed the Vita...)
If they can get an HD main series Pokemon game out, then they're set. Hopefully that rumor about STARS was right.
Honestly, my top worry is whether third party support will sell well. That and whether Nintendo will actually make a proper sequel to SM64/SM Sunshine, because that was the closest we ever got to open world Mario.