This is pretty interesting, given the strong evidence we have that the Wii U was the result of Iwata, especially with what is in the box. Iwata essentially told the hardware department the Wii U needed to be low power consumption and a small form factor comparable to the Wii. The gamepad aside, those restrictions are going to severely limit what can be put in the box due to overheating concerns and you know, wanting extremely low power draw. He really misunderstood why the Wii sold, as it wasn't due to the small form factor and power consumption at all, but due to the controls and a select group of games that helped make them appeal to a broad audience.
Miyamoto obviously has a say, but I am unsure how this was a console tailored for him - Miyamoto's games have actually been among the least impressive on the system, so if it was designed for him then lol, because Nintendo's OTHER development teams are doing a much better job taking advantage of it than he is individually. Even then, there was a masive dissconnect between the Wii U hardware and the development teams at Nintendo and what they wanted, which they feel they have rectified by putting most of those teams in the exact same building. This should mean the next iteration of hardware is more in line with what their game designers actually want, versus the demands of the CEO on form factor and power which restricts everything you can do. We obviously don't know what those dev teams want, but them ore power, the more possibilities.
Nintendo always designs their consoles for their own teams above all else, but the Wii U is the first console they have released that it seems Nintendo's own teams weren't happy with, even if they do great things with it given the tool sets they get to toy with. There was a few examples in the past in Iwata asks/interviews/investor meetings where Iwata all but admitted that the Wii Hardware was all on him and the restrictions he gave the hardware team, and that the software side wasn't even consulted on their desires.