Epic Games Mark Rein made these comments confirming that Wii U could run Unreal Engine 4 if developers chose to port it:
"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."
Epic Games' senior PR manager Dana Cowley added that, "beyond the PC, we haven't confirmed any other platforms for Unreal Engine 4."
So this pretty much confirms that Wii U will be next-gen port friendly with the other systems. Epic Games of course did not tailor make their engine specifically for the Wii U but the system will still have enough modern features to run it. This is more proof that the Wii U has the chance to not get left out of the next-generation of console game development and also not repeat what happened to the original Wii.