A New Media Player Has Been Released - MiiPlayer
A port of MPlayer for the Nintendo Wii
Source - miiplayer - Project Hosting on Google Code
Download Here - Downloads - miiplayer - Project Hosting on Google Code
Look here for the latest beta revision - http://code.google.com/u/gazstone/updates
This is what was included in the readme
Sorry to get your hopes up, but just at it says at the top of the post - A port of MPlayer for the Nintendo Wii. This function exactly like MPlayer CE. I'm sure there are some hidden upgrades that you cannot see, just have to play around with it. Also, remove MPlayer CE from your SD card, then copy miiplayer to your SD card and rename it mplayer_ce, it should then work.