While it's not much to see, but the last part of the recent developer video for Bayonetta 2 had a 1 second monster clip at the end that was assumed to be CGI and not real-time graphics. The director of Bayonetta 2 Yusuke Hashimoto confirmed in a recent tweet that it was in fact a debut of actual real-time graphics from the game itself.
Here is tweet: Link
If that's a glimpse of how built from the ground up games will look on Wii U, then there is no cause for any concern for how Wii U graphics are going to hold up against the competition. Different shades of "pretty" in this coming generation will probably be the norm and whoever has the best art style is going to stand out more when they put these modern graphical effects to use.