"Wii U hardware is on par with current gen consoles"

[SvennoJ]

Back on topic

"We got the game running on their hardware pretty quickly"
"taking advantage of the extra screen and the touch capability and all that"
"we’ll have a few new feature for sure, but I think visually, for the most part, it’ll be pretty much the same."

So they had no trouble to get it to run on the WiiU looking the same as on 360 and ps3 with room to spare to support an extra screen. Looking the same as the heavily optimized engines for 360 and ps3 with 6 years of experience.
That doesn't sound like it's just on par to me. Compare 360 and ps3 launch games to now. WiiU launch games looking at least as good as 360/ps3 end year games without much trouble is a pretty good start.

Anyway why would they bother to spend money on higher res textures and higher polycount models / environments for a new platform with an install base of 0 as of yet. Devs hardly ever bother for the pc version. Improvements will come when the WiiU catches on.