After about 9 months of development, SRC•DX was launched this week - and will ship around the end of the year. Its a low RF noise USB to dual-coax converter that converts a high resolution USB signal into a dual-coax signal. This means 16fs PCM audio (705.6/768khz sample rate) can be input directly from a USB source to a dual-coax compatible DAC—and it's a valid 'DBNC' signal (cyan/purple LED and all).
SRC•DX reveals how good software upsampling can be. I've heard it and I'm betting that it will transform high end audio.