I feel like we've had this same discussion before, but if Nintendo can get a 500 GFLOP range portable at a reasonable price (and I think this is doable) ... they should go for it.
That's their best ticket for success in the coming generation, if they have a powerful portable it will see a lot of developer support from the get go.
The console/dock/companion/whatever other version can then just be your basic PS4+ in horsepower and they both share games, that's probably their best bet this generation. I would probably suggest a few other things but roughly I think unless they have a *miracle* controller again that they have actually product tested with real/normal people and it's blowing people's socks off ... then sure build a system around the controller. But if you don't have that, then a unified platform with a strong portable that takes advantage of the radical leaps in modern portable tech would be it.
If AMD can give Nintendo a portable chip comparable to an Apple A9X or Tegra X1, the A9X is dead even with a Nvidia 730M, and the 730M while nothing special can run PS4/XB1 only games like The Witcher III and Assassin's Creed Unity even at 720p reasonably well:
https://www.youtube.com/watch?v=uJQTFk6wo0U
https://www.youtube.com/watch?v=L7o4l1NEoxs
Nintendo could bring that down even to 960x540 to make it even easier to run if need be, but the above games really aren't even optimized for this specific processor and they still look playable enough at 720p.
