En GBATemp han publicado esto: The homebrew launcher for WiiU is finally here ! This homebrew launcher is developed by Dimok. It allows you to list and launch elf files located on your SD card ...

During this screenshot our SD card was empty, thus the expansive bubbly-goodness of the default Homebrew screen. As you add applications they will appear here.

Now just take the SD card back to your Wii, plug it in, and run the Homebrew Channel again. This time you should see mplayer next to your other installed apps, like below.