hsrob on 02 February 2013
As pointed out above it doesn't matter if it does, insofar as graphics quality could still be drastically different between the WiiU and other console versions of UE4 games. It matters only in that it means, theoretically, that games could be ported relatively easily between consoles.
One thing I am fairly certain of though, the best looking games on the Wii U will not use UE4.
