This is a fairly good idea.
Turn your Wii into a Media Centre
Wii Media Center X is a free multimedia server developed by Red Kawa. It allows you to stream certain types of pictures, music, videos and files from your computer (where the server running) to your Nintendo Wii. It runs on most major operating systems including Windows, Mac OS X and Linux.
Videos - Wii Media Center X lets you stream and watch videos in the Flash video format (FLV) on your Wii. You can download flash videos from many places on the internet or create your own using Wii Video 9.
Music - Wii Media Center X lets you playback MP3s on your Wii without the need of an SD card.
Pictures - Red Kawa Media Center lets you view pictures on your Wii without the need of an SD card.
Files - Wii Media Center X lets you browse your files located on your server.
Wii Media CenterThis is fairly cool, when Opera Enabled Wii comes out I am getting one.
EDIT>
Looks Like that may not even be necessary.
These guys are offering Free streaming music for the Wii Browser
http://www.teknision.com/wii/ I was thinking of doing something like this myself.
I am using it at the moment and its cool, great sound quality.