It would require a miracle, a third party exclusive game out of left field that sells 2-3 million on the console and seems to be only possible on the gamepad. Even then the volume of sales on next-gen systems will eclipse what is currently the norm on Wii U pretty much immediately. Something like Call of Duty, Battlefield, Assassin's Creed 4 or Watch Dogs will probably sell better at launch than the best selling Wii U third party game has done in a year.
I can't picture a future where third parties consider it a good idea to go make exclusives for Wii U. Best bet would be some downports that not many people will care about, might be worth it for certain titles that fit the Wii U demographic once the system picks up in sales a bit but that's a best case scenario.
Honestly as a Wii U owner I'm perfectly fine with this scenario, I just want Nintendo published exclusives, third party games would run/look better on PS4 anyway. The gamepad certainly hasn't proven itself to be a big deal to me, in fact the battery life on the controller is pretty pathetic due to the screen and Nintendo cheapening out on the battery. Would much rather get third party games on PS4 and I'd wager most gamers will feel the same.