I still think it's likely that the game will be released some time in 2017, perhaps with the console NX release.
The graphics shown just seem too good to be able to run on a Wii U, in my opinion. I mean, clearly, the lighting is done is such a way that it looks more beautiful than it ever would in-game (literally every trailer does this, though), but I dunno. Zeldas take a long time to make. Open-world games take a long time to make. HD games running on a new engine take a long time to make. I don't think it would be that preposterous if it needed some extra time.
In any case, if it comes to NX in any fashion, I will most certainly get it.