At first I was concerned about the price being too high, but it looks like I was wrong and people are actually willing to pay that amount for the concept.
Now, I'm somewhat optimistic about it doing much better than the 3DS (maybe even reaching 90m), BUT it still has the shadow of the mobile market hovering over its head. I mean, you can say whatever you want about mobile gaming, but the fact remains that the handheld market has seen its install base reduced in more than 60% in the last gen, and is all because of it.
In the end, I think Nintendo made the right decision by making the hybrid concept, BUT we should try to imagine where the mobile market is gonna be in about 4 years. For example, I see that the A10 GPU and the Adreno 540 (present on the iPhone 8 and Galaxy S8) are almost as powerfull as a fully clocked Tegra X1. And yes, those are really expensive phones today, but I'm sure in four years that level of performance is gonna be pretty commom for a lot less than $200.
And I'm also willing to bet that the ability to conect your phones and tablets to your TV is gonna be a commom practice from here on (many phones and tablets were able to do it way before the switch, its just that people didn't know it).
Soooo, to sum things up. I'm cautiously optimistic about it.