There won't be an AC for the Wii U IMO. The producer of the series even said the series works better as a handheld game and while they were looking into a Wii U version it could end up on "another platform".
The other platform is the next Nintendo handheld, where this game would sell a lot more than it would on Wii U.
So I think that's a rather easy decision for Nintendo.
The Wii U is already getting Splatoon anyway from members of the AC team.
If it was coming from Wii U it would've been shown already too IMO. They've shown Zelda and other late 2015 games, but nothing on Animal Crossing, not even an announcement. Doesn't make sense.
The next Animal Crossing will be a launch window title for the next Nintendo handheld and will sell over 7.5 million WW, 3 million+ alone in Japan. It will be an evergreen title that sells as the system base grows.
And that will be the smart move, AC on Wii U alone would sell maybe half that, putting it on the next handheld makes much more sense.
