A handheld + home VitaTV like box are "seperate" devices but still linked. 

Just like iPod Touch + iPhone + iPad are seperate but have the same OS and similar chipset architecture and the same app ecosystem. 

So what Iwata has said doesn't really go against what I've said, in fact if you read his overall comments more carefully, they're much in line with what I'm suggesting. 

Miyamoto has also commented in the future they'll make one game but it'll work on multiple hardware. Iwata has also said Nintendo needs to adopt the iPad/iPhone style format, where you have one ecosystem just playable over different form factors. 

IMO you'll have a "Nintendo handheld" launch in spring 2016 or thereabouts. This effectively IS the next generation Nintendo format launch. 

Then in the later months you'll probably see a Vita TV like home device which lets you play the games on your TV if you wish. But same library, I think even same chip components, it'll just be scaled a little bit so that the handheld plays Wii U quality graphics at 960x540 30 fps (for example) whereas the TV version has dual/triple chip so that it can run the same game at 1080p 60 fps. But even that isn't very different from the iPhone/iPad, where the iPad apps run at a higher resolution and it has a slightly better chip. 

Once Zelda U is finished, I think Nintendo is pretty much finished with the platform.

I think maaaaaybe Retro Studios might be doing something like Diddy Kong Racing U as the swan song in 2016.

By that time though Nintendo will have given the Wii U all the major Nintendo IP. There's no point in dragging out an unsuccessful console. It just hurts the company by devoting resources into a dead end.

The GameCube really didn't get 5 years either, Nintendo pretty much stopped supporting it after March 2005 with DK: Jungle Beat's release. The rest of the major games were basically outsourced projects and Zelda: TP was moved to be a Wii launch title with the GCN only getting a limited, late release of the game. 

Back in May Nintendo announced that they would not release new hardware until current Wii U owners are satisfied, since then E3 has come and gone and we now have a better look at what Nintendo has coming from now til the end of next year. Would it be realistic to say Wii U owners will be satisfied by the end of 2015? Here is the list of exclusives from launch to end of 2015 that we know of now, assuming that none are delayed.

New Super Mario Bros U

Nintendo Land

ZombiU

Monster Hunter 3 Ultimate

Lego City Undercover

Dragon Quest X (Japan only so far)

Game & Wario

New Super Luigi U

Pikmin 3

Wonderful 101

Wind Waker HD

Wii Party U

Wii Fit U

Wii Sports Club

Sonic Lost World

Mario & Sonic at Sochi Olympics

Super Mario 3D World

Donkey Kong Country: Tropical Freeze

Mario Kart 8

Hyrule Warriors

Fatal Frame V (Japan only so far)

Bayonetta 2

NES Remix 1+2

Sonic Boom

Captian Toad Treasure Tracker

Super Smash Bros for Wii U

Mario vs Donkey Kong

Xenoblade Chronicles X

Kirby Rainbow Curse

Yoshi's Woolly World

Mario Marker

Splatoon

Giant Robot/Project Gaurd

Shin Megami Tensei x Fire Emblem

Devil's Third

Star Fox U

Mario Party 10

Legend of Zelda U

Diddy Kong Racing (rumored)

Pokken Fighters (rumored)

2015 remaster (rumored)

On top of that we have a decent selection of multiplats, Call of Duty Black Ops+Ghosts,  Assassin's Creeds 3+4, Darksiders 2, Mass Effect 3, Ninja Gaiden 3, Resident Evil Revelations, Deus Ex, Sniper Elite 2, Walking Dead, Splintef Cell Blacklist, Lego Batman 2+3, Lego Marvel Super Heroes, Lego Hobbit, Lego Movie, Disney Infinity 1+2 (probably 1-2 more), Skylanders Giants+Swap Force+Trap Team (probably 1-2 more), Just Dance 4+2014+2015 (probably 1-2 more), Watch Dogs, Project Cars, Batman Arkham City+Origins, Rayman Legends

That list covers the majority of major Nintendo titles, Metroid/Animal Crossing/Paper Mario being the only big ones not represented, so could we see Wii U support start to drop after 2015 with a new console in late 2016?

Nintendo will NOT break the 5 years min cycle. If they do, I'll leave this site forever.