The end of 2016 is the absolute soonest I'd expect a new Nintendo console. Anything sooner would piss off existing WiiU owners and would've give them enough time to get ready.

I'm expecting 2017 myself, though. Has Nintendo ever put out a console less than 5 years after the last one?

Too soon imo.
A spring or even fall 2017 release will assure SW is ready, and will have a strong first Christmas season thats not a launch.

If this is gonna be a home console and a handheld in one I predict its gonna be weaker than the PS4.

they showed Wii only 4 years after GC launched Showing new HW at e3 2016 is not out of sight at all

I think it will be even sooner than that. Fall 2015 for the next Nintendo handheld which will contain the new architecture and the same games as any future console (I think the console itself will be more akin to a dock ... almost like an accessory).

3DS is already fading, Nintendo won't go until 2016 without something to spike their business and while all that QoL talk is nice, that's a new business field for them and it could take them years to get established there. 

Would not be surprised.

http://gamrconnect.vgchartz.com/post.php?id=5891288

That's a pipe dream. I don't see it happening. 

It would destroy the whole point of a scalable platform if one was far more powerful than the other. The next Nintendo "console" will be a home version of their handheld chipset, perhaps just beefed up so the games can be displayed in full HD resolution (1080p) and look purdy on the TV.

ARM cores and mobile GPUs scale very easily, so you could have a 4 core variant for the handheld and an 8 core variant for your "console", no problem. Samsung even does this for their same smartphone models (the Galaxy S4 has a different number of cores for different markets).  

That's it. The handheld is going to be the star of the show. 

I think it's too early.

E3 2014 - details about the QoL platform, new games for Wii U and 3DS
2015 - release of the QoL platform and at E3 we will see new information about all the 3 systems they have until that day
2016 - announcement of the next generation
2017 - release of the next generation

and that would still be early. Maybe you will be right. But that would mean Nintendo would stop his whole policy and do it even worse. As I already mentioned I don't think so but never say never.

It will be the same thing as the iPhone -- iPad.

The iPhone is actually the "lead" platform really, the iPad gets the same chip, just beefed up in cores/RAM occassionally so it can drive a higher resolution screen.

But keeping them mostly the same (same chipset more or less) allows iOS devs to port (or really "upscale" their games) easily and keep the experience the same more or less.

The consumer is free to choose on what device suits their lifestyle best to use those apps/games on ... that's what's going to happen with Nintendo "consoles" (though I don't think they will resemble consoles anymore).

This model could also enable faster hardware refreshes too ... if the software library is effectively "liberated" from being a slave to one platform, and the platform is really just up the consumer's taste (whether they want a tablet form factor, a cell phone form factor, a home TV form factor, etc.) then the hardware can be refreshed more often. 

I'm talking more in terms of actual release dates.

Only the DS and GBA comes to mind; those were released 4 years apart. As far as home consoles, 5 years has been the soonest for each one I think.