AES/EBU is just balanced S/PDIF.
Ayre's asynchronous USB implementation is courtesy of the software written by Gordon Rankin of Wavelength Audio, which Ayre licensed. dCS also has a true asynchronous USB implementation and apparently Resolution Audio's new unit does also. Some other companies throw the term around but I don't think they are legit async USB.
The Weiss Minerva mentioned above, which is now replaced with the new DAC202, uses Firewire, not USB.