Not sure if this has been posted as of yet. One of the devs from Helix Games made a post on reddit asking if people would want a Media Player for Wii U. Could be interesting if this goes anywhere.
Source
Original post on reddit
I'm one of three developers at Helix Games, and right now we're looking into developing a media player for the Wii U. You would need to transfer the media over LAN, but it should be able to be stored on the Wii U's flash storage.
Nintendo have some funny regulations with non-game software, so nothing's set in stone. However, we'd just like to verify that there's enough interest before we commit resources to this.
Source
Original post on reddit