2008 and 09 will see huge leaps in the usb based streaming audio device market. My little UD-10 is a first generation product that does more to reduce jitter and emi than I have previously had.
USB is the deal with vista. Truly remarkable sound. As a PC transport, it is tops.
Though somewhat unrelated, I'd like to mention that you could also eliminate these issues by not using Creative hardware.
If you want to give them more of your money, though, that is, of course, your choice.