As previous users have mentioned, there's only three emulators right now and at pretty young stages of development.
GBiine, the Chip8 and a NES emulator.
Right now all hope lies on RetroArch and its development team, and QuarkTheAwesome too.
I know Quark was working on getting it to work: https://github.com/QuarkTheAwesome/URetro
But the RA team has said that they haven't developed anything for Wii U yet because the development team does't have a Wii U.
So I don't realy know what will happen after that.
Quark said he was going to contact the development team to seek help, but that's the last I knew.
Sad isn't it?
They should be the ones getting a Wii U through donations instead of Hyk- Oops, almost let it slip.
At least we know they would deliver he goodies for sure!
I mean, come on, RetroArch runs in almost every console from the 7th Gen and onwards!
Even phones and other stuff! Even my toaster runs it!