Zelda is most likely coming for both the NX and the Wii U. How much different will they be? I think Nintendo might want to maximize NX sales since it's imperative to there business and money making strategy . If Nintendo makes the game the best it can be on Wii U I'm sure people that don't want to upgrade to the NX will still buy it on Wii U.
I think they could keep the same cel-shaded style while "piling on" more effects if they want to take advantage of the added horsepower. I'm excited to finally see this game again hopefully soon. Also, if they use Vulkan on Zelda NX, the graphics would be able to push way more grass/trees/draw distance on screen than the Wii U version and all at 1080p/60 fps. The control and gameplay might be the same on both versions though.