Whenever we post an article about the Wii U YouTube app, we're reminded multiple times that it's better to use the web browser. So, early disclaimer - it is arguably better to use the web browser for YouTube on the Wii U, no argument here.
Still, the actual app is a thing and Google continues to roll out occasional updates. There's now a fresh version awaiting Wii U owners (hat-tip to Wii U Daily) which spruces up the overall look of the interface, representing a stylised variation of the layout users of the web version and other app iterations are used to. Unfortunately, though, it still doesn't seem to stream 60fps videos, and you still need to use the GamePad, with the TV screen showing a blank logo until a video is playing - sorry, Pro Controller fans.
But yes, it's probably still better to use YouTube in the web browser.
With thanks to Ryan Millar for the heads up.