Well, more or less anyway. Understandably Toshiba didn’t want to make things too easy for them.
Apparently, while they have superuser permissions on the device, they still aren’t able to read or write to the system directory. More interestingly, they haven’t been able to get the Clockwork Recovery image to stick very long because the Thrive reflashes its own stock image every time it reboots. Very clever, Toshiba.
Still, given that Toshiba’s chubby portable has only been available for a hair over two weeks now, this is quite the accomplishment. What makes the whole thing more impressive is the fact that one of the project’s main devs, a chap who goes by the handle DJ_Steve, is based in the UK where the Thrive hasn’t even been released yet.
Feeling adventurous? Full instructions are available on ThriveForums, as well as the specific bits to make it work, but do so at your own risk. Bricking a shiny new toy isn’t pleasant, and you don’t need to take my word for it.
EDIT: Updated to accurately reflect TabletRoms.com’s role in the project.