One of the points that was made over in computeraudiophile.com is to have your data streams separated from each other. Example being if you are running a USB DAC to use a different interface with your external music storage device (Firewire, Ethernet or eSata) Many look for a micro ATX board with eSata, or add an eSata card to their systems just to have the speed of the eSata, and to have it separate from their DAC.
On my speaker system, I will have my NAS via wired ethernet from a Drobo server fed to a MacPro, then USB to a W4S Dac2 when it arrives next week.
Further plans will be for a MacMini music server with an attatched firewire storage device (backed up to the NAS), controlled with remote desktop and using either Remote on a iPod Touch, or yTrack on an iPad. Either that or I will go back into the DIY PC scene again, and make a PC based server in a small fanless case. I could get eSata in that, and be able to build to order better than with a MacMini.
Many comments that any additional speed given to data transfer "can" improve sound quality. I personally believe in getting your music files out of the computer, and using the fastest interface you can use for that, as well as not "crossing the streams" to use an old Ghostbuster's term.
Edited by Bones13 - 8/28/10 at 6:24am