I read the FIFO thread on DIY Audio the other day. The work Ian did is so pro, it is a rarity.
The concept is not new though. PS Audio Genesis Audio Lens, and even SqueezeBox has the same idea. Just think of SqueezeBox as a Wi-Fi DAC, with a FIFO in between. The parts where the SqueezeBox failed are that they did not reclock the output with a Picogate flip-flop and did not use a good clock. If they did, the sound would be really up there.
Anedio U2 did the reclock with Picogate flip-flop trick, except they did not have good clock. This is why out of all things in the D2, I only modded the clock in U2. Obviously, lots of manual labor was involved and not some automatic assembly like Ian's FIFO board to reduce cost.
So what clock are you using with Ian's FIFO? CCHD-957?
I know there are hardware that does DSD over USB, Mytek 192 Digital being one commonly available one. The questions are implementation and software. Whether the hardware is going to sound good depends on the implementation and the clock. As for software, how many native DSD encoded music are out there? Doing SACD rips is no easy task, one needs to have the original PS3 with hacks in order to do that. And even that, many SACDs were not recorded in DSD to begin with.
Finally, don't expect the CCHD-957 to sound superb automatically with just a low noise or high PSRR supply. There are tricks involved, as I've been playing with this XO since Nov last year 
Edited by Viper2001 - 9/1/12 at 7:01am