Maybe I'm out of the loop. Are kids playing the 3DS or any other handheld in droves at all? This just looks like a less cool version of that to me, in terms of a handheld device. Maybe kids will disagree, but I would think the novelty of 3D without glasses would be more of a wow moment for little kids than this.
I'm guessing this thing will be more money than an older version of PS4 or XB1 by the time it comes out, so I can't see the console element of it being all that appealing, especially if they have kids of varying ages. But yeah, if kids really love 3DS as much as they loved Gameboys back in my day, I could see that catching on to some degree. Maybe.
The other thing is if the thing is relatively expensive, which it will be because Nintendo, are you even going to want your kid to go to school with a modular electronic device, knowing that the kid could come back with one controller not attached anymore or something? Again, I dunno.