Neither am I. I received the news in an e-mail from the Norwegian importer which I bought my Lynx Hilo from, and then searched for some information before writing a post about it on the Norwegian forum Hifisentralen and on Head-Fi.
If I haven't misunderstood the information I received and the information on the Lynx site I linked to, anyone can buy the Lynx LT-TB Thunderbolt LSlot Interface for Lynx Hilo and install it themselves. If the Hilo already has a card installed (ie. USB), you must remove it before the new card can be installed.
The Lynx LT-TB Thunderbolt LSlot Interface needs a new firmware version. I don't know whether one may run the firmware update after installation of the new card or it should be performed before card swap.
I'm under the impression that the Thunderbolt interface/protocol have much higher bandwidth and hence can cater for a lot of high resolution channels at the same time. You can also chain several Thunderbolt units and use them in consert.
I think I saw somebody writing about (possible) reduced latency as well.
I assume that most two channel listeners are well off with the USB card, but I may be wrong.