Wii U is a 45nm chip..
If Nintendo went with a 16nm FinFET single chip (apu), they could probably cut that 75watts down by ALOT (like down to 20watts or so).
Good point, although Nintendo most likely wouldn't go with the latest (and most expensive) designs. For example, Intel was shipping 22 nm Ivy Bridge processors in 2012, while Nintendo used 45 nm for the Wii U.
A 28 nm design is more likely, so that would bring it down to about 45 Watts.