It “SEEMS” like Nintendo has already started working on some form of next generation machine. That is, if a NeoGAF poster is to be believed. Get his exact words past the link.

From NeoGAF user wsippel:

“Almost certainly off-topic, but I don’t quite want to make a new thread, because it would go to shit quickly. Also, I’d need to post a source, and I don’t really want to get people in trouble.

Anyway, Nintendo apparently started working on a new platform in early 2013 and has already selected a vendor for the SoC after talking to several potential candidates. The SoC might be based on an existing design, but will be changed to fit Nintendo’s requirements. I assume it’s for their next handheld, though.”

PE’s Take:

Guys, I want to let you know I have also heard information that Nintendo is indeed working on a next generation machine. But my info points to a handheld with console like power, not a new console. Those rumors about the next gen of Pokemon a couple weeks ago….yeah, those might be true…..just saying. And if you watched the PE Network Vidcast 2, I predicted we would start hearing the first rumblings of Nintendo’s next generation machine…

The 3DS JUST came out...

It's been out a few years.

I don't know why their working on a new system. If it's a home console, the Wii U is great, it's just their marketing was terrible. There are still a ton of people that think that the Wii U is a Wii extension.