I've often enjoyed them as a nice little pre-game touch, so it's awesome to see NeoGAF user Oni Link 666 rip out some Wii U game loading screens and dump them for use as wallpapers.
There are 48 screens in all (some from cutscenes, most from loading screens), each at 1920x1080, and while some were probably more suited to being console loading screens than desktop wallpaper, others (Samus, Link, Duck Hunt) are just perfect.
Wii U loading screens [NeoGAF]