I have been looking into some of the options for streaming music from my WHS to devices in my house.
So far I don't seem to be finding many good options. There are some that you point to a UNC share and then have to deal with a crappy UI to select the songs you want.
2 of the nicer options I have see are:
http://www.sonos.com/howitworks/
and
http://www.roku.com/products_soundbridge.php
http://www.roku.com/products_soundbridgeradio.php
I'm going to have to keep my eyes open for other options, but these seem like viable candidates.