Nintendo's games on Wii U already look pretty great to be honest.
If they can find a way to get Wii U level hardware performance from a mobile chip, I'd be fairly content with 3x the performance of the Wii U (meaning just throw three of those processors into a small box and call it a day).
That's a nice sized upgrade.
Nintendo doesn't want to compete with Sony or MS, so making some expensive uber-console is not happening, something cheap that still looks great and probably has a few (cheaper) gimmicks thrown into the box .... I mean if its coming in 2017 .... wouldn't be the worst thing in the world IMO.
The GameCube to Wii jump sucked because there was like literally little/no hardware upgrade, if the next NX console version punches in at the 750-800 GFLOP range even, that will be a nice upgrade over the Wii U.