iPod to DAC Connection

I was disappointed that the fourth generation iPod announced this week did not have a digital output so that it could be hooked up to an DAC. I think it could provide near audiophile caliber output if you used the best AIFF or Apple Loseless processing options and a digital output. Now, I'm wondering if it is possible to have a digital output for it by somehow hooking up a cable to the iPod itself or the dock that would be Firewire or USB 2.0 at the iPod/dock end and S/PDIF at the other end to plug into a DAC. Anyone know if this is possible? Does such a cable exist, or maybe the digital bits coming out of a Firewire output are different from those going through a coaxial data cable? Any insights would be appreciated.