OK, I heard from James at Anedio, so I'm adding a status update.
He tells me that the USB to SPDIF converter is "essentially done". I get the impression that the design and build is all complete, but there are just a few minor odds and ends to take care of. Maybe something like the manual, or final touches on the enclosure, or something like that. With the main focus being on the updated DAC, this product has probably been low priority, but I imagine they will be available for purchase soon enough.
He also tells me that the D1 update is moving along well. PCB will be sent out for fabrication soon, and unless there are unanticipated issues, the project will move forward. Next step after that would be EMI conformance and safety testing by an outside lab. To paraphrase James, who described the updates in his typically humble way:
He made far more changes than originally anticipated, although all are still minor/incremental. Changes to power supplies are sprinkled throughout the DAC. Special attention was paid to the DAC analog power supply. He voiced his displeasure with the way it was handled in the ESS demo board, but lacking detailed information on the internals of the ES9018 chip (apparently ESS was not very communicative with him on the subject), he was limited as to the improvements he could reliably make while designing the original D1. With knowledge gained from the initial D1 build, and lots more time spent on it since then, he believes he has improved it. Jitter will be even lower, and the headphone amp will be better as well (no specific details given to me at this point regarding amp upgrades).
That's all I have at the moment. Still no specific time frame information. Barring any complications, it seems that it will mostly come down to the time it takes for certification by the independent lab.
