here's a few wireless devices...

creative sound blaster wireless. works over your wireless network, and has a remote for the music on your pc(HOW COOL!). optical digital out from the receiver.
www.creative.com/products/product.asp?category=243&subcategory=247&product=9192

the d-link here streams HDTV/muisc and almost anything else, but it looks like you need a very rescent pc to run it.
www.dlink.com/products/?pid=542&gclid=CIDi9dnvwY0CFR8TOAodFHfuLQ

another d-link, for music only.
www.dlink.com/products/resource.asp?pid=457&rid=1746&sec=0

sean