Here is a pretty cool product line of products that will let you display your computer audio and video contents on your AV system. It looks like they have a server product that will transmit content to up to 4 client products. It looks like the client product will also play content off of a PC or a Network Storage Device.
The SkipJam iMedia center will play MPEG 1/2/4, MP3, WMA, WAV, Ogg, JPG.
I am not sure that I am all that interested in this. The SkipJam iMedia Player seems not to be worth $499.