Activision; Ubisoft & Warner all consistently release games from their biggest franchises on WiiU. Not all of their franchises, but from some of the biggest sellers at least.
Sales data:
http://www.vgchartz.com/gamedb/?name=&publisher=&platform=WiiU&genre=&minSales=0&results=200
is beginning to paint a picture of what sells and what doesn't on the console. If you have a family-friendly IP (Skylanders; Just Dance; Disney Infinity; Sonic), your game will sell pretty well. If you have a more mature themed title (Assassin's Creed; Call of Duty; Batman), sales won't be as strong.
This is particularly highlighted when you compare to the sales of PS4 & XB1:
http://www.vgchartz.com/gamedb/?name=&publisher=&platform=PS4&genre=&minSales=0&results=200
http://www.vgchartz.com/gamedb/?name=&publisher=&platform=XOne&genre=&minSales=0&results=200
WiiU versions of things like Skylanders or Just Dance put up similar - if not better - numbers than their Sony/MS counterparts. Whereas games like Assassin's Creed/Call of Duty/FIFA get absolutely obliterated by their Sony/MS counterparts.
For the time being, it seems like WiiU will keep getting the big games from the big publishers, but I question how long it'll be until we get a partial withdrawal of support with them keeping only the family-friendly titles on the console and not the more mature games.
Other publishers like Take-Two & Bethesda haven't really committed to any next-gen consoles yet. I'd imagine when they do, it will be PS4/XB1 though and there's very little Nintendo can do about that. I'm sure they were doubting going to the console in the first place and the weak sales of similar games will be the nail in the coffin for any ideas they had (if they did indeed have any).
Some publishers like EA never committed in the first place. I'm sure lots of behind-the-scenes shenanigans and bias will be called, some of which is probably correct, but judging by sales figures EA probably made the right decision. They could've given it more of a go, but I'd imagine the end result would've been largely the same.
Japanese publishers aren't really jumping onto home consoles at all. What few titles are coming out were locked down by Sony/MS long, long ago.
So all in all, there's not much Nintendo can do at this point. Their opportunity was during the whole year ahead they had, when they should've tried to build up the userbase and build up the sales of the third party games they had; as well as liaising with other western third parties to port their games across. As it stands, neither of those things happened, and they'll have to be content with taking whatever they can get; because it would be a hard sell to get a new third party on board these days when their games are likely to be outsold 6:1 by the version on competing consoles.