From: DivineTruth | #005I think most gamers are gonna be pleasantly surprised when it comes to whether or not Epic makes a UE4 engine tailored to the Wii U. ;)
"Rein: "I'll state that I don't think it's our intention to bring Unreal Engine 4 to Wii U, but Unreal Engine 4 is going to be supremely scalable.
"We'll run on mobile phones and on a wide variety of things, so if a customer decides they want to port an Unreal Engine 4 game to Wii U, they could. But Unreal Engine 3 is a really good fit for that platform.""
http://kotaku.com/5925575/good-news-and-bad-news-for-those-concerned-about-the-wii-us-power
I guess Square Enix could make lesser titles for the Wii U, it did happen on the Wii so anything is possible.