I don't really care, as long as Nintendo keeps making games I like to play. I do think the industry would sorely miss their batshit crazy hardware antics though.
Kinda cool to think if they went handheld-only. All their IPs only on one system? They'd make a crapload and put the PSP/V line in the ground.
But really, Sony deserves to go console-only before Nintendo goes handheld-only. PSP had 10 minutes in the spotlight before Sony turned almost all its attention to PS3, and I see this being repeated with PSV/PS4. They're not as good at juggling two systems as Nintendo, but even Nintendo has trouble with it (see: Wii in 2011.)
But anyways, I remember the Dreamcast being quite revered and having some of the best first-party games ever. If that's Wii U, sign me up.