Audioengine has released a software independent, wireless music streaming solution, called the AW1. The AW1 set contains a receiver module and transmitter; the receiver connects via USB, RCA or line-out and the transmitter connects to your PC via USB. The audio sent is then picked up by the connected audio source, with a reported 100-foot range.
Interestingly, the transmission method is unique to Audioengine, which uses their own AvenraAudio technology. We're not too sure how that sounds, but it supposed to churn out CD-quality output with no dropouts or static. At US$149, it may be worth the investment if the sound reproduction is as good as they claim. [Audio Junkies]