The Nintendo Wii U Scene Is Getting Much Better!This is still a WORK-IN-PROGRESS as such its mainly only useful for developers, but hey why not try it out anyway and enjoy some Mario!
Finally now, those with a modded Wii U console running 'custom firmware', you can enjoy loading games from your USB HDD!
For more info, check out all the links below:
GITHUB: --> https://github.com/dimok789/mocha/commit/43f1af08a345b333e800ac1e2e18e7aa153e9da9
GUIDE: --> http://gbatemp.net/threads/playing-loadiine-games-from-and-hdd-thanks-to-mocha-cfw.460774/
NEWS SOURCE: WIP: Mocha CFW native USB hard drive support (via) EurAsia