Epic co-founder Mark Rein categorically (and quite brutally) ruled out Unreal Engine 4 running on the Wii U in a Q&A session with Kotaku. Here are the relevant exchanges:
Kotaku - Will UE4 run on the Wii U?
Rein - Hahaha no
The room then 'erupted with laughter', before Rein continued:
"Unreal Engine 3 doesn't disappear because of Unreal Engine 4. But our goal for Unreal Engine 4 console-wise is next-gen consoles. That's really what our energies are focused on. If you want to make a Wii U game, we have Unreal Engine 3, and it's powering some of the best games on the Wii U already."
You can check out the full-length 'infiltrator' demo trailer for Unreal Engine 4 below: