splatoon may be wiiU's biggest stand out game but that is mostly because the lack of any other contenders. splatoon received next to no GotY nods and outside of vgchartz seems to already be a forgotten game.

Fixed.

I think the best way to sum up the Wii U's legacy will be "the system tens of millions of people *almost* bought."  Because that's been the tone since mid 2014 it seems.  People on the net, in stores, etc being on the precipice but never actually buying.  Waiting for a price drop that never came , or needing that final push in the form of marketing Nintendo wasn't willing to spend for.  If the Nintendo had marketed more aggressively and the Wii U had gone to $250 in holiday 2014 (or just gotten a Smash bundle) or at the Splatoon launch or heck even THIS holiday, sales would have improved a lot.  Those few brief weeks where the price was $250 at multiple stores, Wii U saw a nice surge in sales followed by a massive plummet when that was no longer available.  Mismanagement of the price, inconsistent bundling, and unwillingness to increase advertising presence even after spending the money to improve the Wii U's marketing all doomed the system from the word go, lineup and 3rd party suport (or lack there of) be darned. 

Assuming the Wii U generation is rapidly coming to an end, I think Spaltoon will go down in history as the game of the generation for Wii U. Though ultimately it was unable to actually achieve anything beyond its own success since it didn't really break Nintendo out of it's own long held public image. It obviously wasn't intended to so that's not a criticism of the game, but if Nintendo thought the game had any kind of strategic role for Nintendo's home console aspirations they were badly mistaken. So if that was in the minds of the Nitendo execs then it is a criticism of them for continuing to mis-understand the broader gaming market outside of their own core fanbase.

-Like I wrote, Zelda U and NX will probably be released in same year same like TP and Wii, that wasn't case with SS.

-Wii Sports bringed casuals but TP bringed core gamers  You are in delusions if you think that TP didnt had any impact on Wii launch. GameCube had all that but PS2 was too strong too compete with it. Like I wrote, Wii U had many problems, but very weak launch and 1st years titles are definatly one of problems Wii U had. Unlikly PS/MS Nintendo exclusives are selling Nintendo consoles, for comparison just look PS4/X1, 3rd party selling those consoles not exclusives. Pure fact is that Wii Sports and Zelda TP were much stronger launch titles than NSMBU and Nintendo Land, but you can ignoring that if you want.

-Zelda U can be system seller and more important title that will bring attention to new Nintendo console.Skyward Sword arrived on already dead console from which people for quiet time migrated to other platforms, also require Motion Plus addon, so not exactly same thing like being brand new, first HD, beautiful true open and biggest ever Zelda on totally new platform. 3D Mario will probably be at launch, maybe Pokemon also, they cant prepare MK9 or Smash for launch.

To sum it up:

You dont know what NX it, how powerfull it will be, how expensive it will be, when it will be launched.

All that is UNKNOWN.

Only, and ONLY if all this parameters will turn on like you are guessing now, there is an chance at all that zelda wii u will be on NX (cross release).

Lets calculate the probability:

1. NX needs to be release in 2016. Nintendo never did this. Nothing hints a 2016 release. I give this a 50% chance to be true; 50% 2017 or later. 

2. NX needs to be a home console or a combination of both. 3DS is older then wii u. It will get a successor first. So only chance it, NX will be the fusion concept. That could be right, also couldnt be right. We dont know. Nintendo said, NX wont replace Wii U and 3ds, but they also said the same about DS wont replace GBA. I think its a 50% chance that NX will be a replacement for wii u and 3ds (and will be powerfull enough to run zelda wii u).

3. Nintendo needs to wastnt to release Zelda Wii U on NX. Even if both points above turn out to be true, Nintendo also needs to want a cross release. It was always a unwritten rule, that every home console system from Nintendo will get its own Mario, Zelda, Mario Kart and Smash game, The 4 big home console franchises from Nintendo. This wont be the case for wii u. Considering Wii U´s low sales and all the Zelda remastered and spin offs it got (Windwaker, Hyrule Warriors, Twilight princess) it may be likely they want to compensate this.

There is one point however which stand against this. All 3 mentioned zelda games (HW, WW, TP) were released, or at least in development before Zelda Wii U got delayed. So assuming Nintendo brought this 3 games to compensate the lack of an exclusive wii u title doesnt make sense. Windwaker was released 2013, HW 2014 and Tantalus already spoke about their Wii U Remaster in Dec. 2014. In Dec. 2014 Nintendo told us Zelda will arrive 2015. So all 3 games arnt made to compensate Zelda Wii U´s cross release. 

Sum Up:

Pro Nintendo want cross release:

- Poor Wii U Sales

- Their biggest project yet on their unsuccessfullst system

- Give NX a boost

Contra Nintendo want cross release:

- Break the unwritten one exclusive zelda game per console rule (Nintendo teases zelda wii u till the reveal of the console)

- Make Wii U owners sad who got the system just for the promised Zelda game (probl wont buy NX because Zelda NX might be on NX sucessor too)

- Alot ressources would be necessary for the port (NX probl. different hardware-architecture then Wii U). 

Considering all above, ill give it a 50% chance Nintendo wants Zelda Wii U on NX at launch.

So do the math. We got 0,5x0,5x0,5 = 0,125. So all in all there is a 12,5 % chance Zelda Wii U will be on NX. Thats not likely or anything.

PS: I will made a new thread with this calculation, this thread isnt about zelda wii u.

-I already wrote you why that's so likely, because whole situation with Wii U and Zelda U is very similar to TP situation and GC.

-Mario Kart never was released only 2 or 3 years after after previous Mario Kart, so it's very unrealistic to expect new Mario Kart this year, but I could definatly see it at end of 2017. or in 2018, that means around 3.5-4 years after MK8.

Also already written, I assuming what NX could be and when will be launch. Based on that I think Zelda U will launched on NX at end of this year. Its clear like day that Zelda U will all over again TP, despite NX want be upgraded Wii U like Wii was in comparison with GC.

1. Actually lotta things points on 2016 NX release: no single bigger announcement for Wii U that isn't smaller project, port, or spinoff for around year and half (from E3 2014.). Almost evre report and info is point for 2016 relase and I will mentione you just few of them, Digitems report, Wall Street Journal report and Nomura Securities report. Nintendo president in message to investors for 2016. plans did not mentioned at all WiiU/3DS, but he specifically talked about NX with other staffs Nintendo planned to release in 2016 (mobile games, new services..). 

2. NX will be home console, hybrid or most likely NX handheld and NX home console. Definitely will not be weaker than Wii U so it will run Zelda U.

3. Releasing Zelda U port like NX launch title will be very help NX launch and sales of game it self, it will win-win situation. Like I wrote, Zelda U not being Wii U exclusive doesn't matter at all that doesn't affect nothing, its not like they will not relase at all Zelda U on Wii U, especially now when it seems that Nintendo plan with NX is to release one game for multiple devices.

I agree with your reasons why Nintendo will made Zelda U cross release and I will add "much better sales of game if its cross relase" and "Nintendo already done something simialar with TP", but I dont agree for reasons against.

-Alaready writen but, Zelda U not being Wii U exclusive doesn't matter at all that doesn't affect nothing, especially now when it seems that Nintendo plan with NX is to release one game for multiple devices.

-Zelda is promised to Wii U owners and they will get Zelda, its not like they will not get at all Zelda U on Wii U. Releasing Zelda U on NX too don't change anything, especially today when we have so many ports.

-Port costs will be very paid up of sales of Zelda U on NX, not mention positive financial effects being launched on NX.

You basically have very strong reasons why Nintendo will port Zelda U to NX and very weak reasons why Nintendo shouldnt do that, and we also already had something similar with TP, so you can't say chances are only 50% that Zelda U will be NX launch title, I would say chances are around 80-85%.

Edit.

I moved answer to new thread you made.

Yes, absolutely, Splatoon is iconic.

The gamepad really doomed the Wii U because of its expensive manufacturing costs.  If Nintendo had just dropped it back before Maro Kart 8 came out, they could have probably lowered the console price by 100 dollars and unofficially be seen as the perfect secondary console for PS4/xbox one and PC owners.   The fact that Splatoon is still selling well and is still garnering a lot of interest online shows to me that it might have saved the Wii U from an even worse fate sales-wise.

Nintendo couldn't dropped gamepad because they already had millions of manufactured gamepads. Also it would lower price of console for $100 because manufacture cost for games were $60-80 and you need to include cost of Wii U Pro controller that would come instead gamepad, no price could be around $50 less for Wii U without gamepad. Saying that lower price wouldn't change anything because Wii U had to many problems that only price cut could change that.