cbee,
Using a computer as a source has been a popular trend in high end audio lately. Some of the best sound at this year's Rocky Mountain Audiofest were using hard drives as source. People aren't using the computer as a transport (only to rip onto the hard drive in tact at 1411kbps), but rather the hard drive as a digital source. Pmbuko is right about the analog output being the critical stage and this is where the rubber hits the road. Look on Audio Asylum, they have a pc audio forum. These guys swear by this method of digital playback.
