My guess is that it will be a slimmed down 6008 body - without the motor drive (now unneeded) but still maintaining (hopefully) the lens mounts for the wonderful Rollei lenses.
Alternatively, it could be a 645 RF type, compact, but with a full sensor. Sort of like a digital Mamiya 6/7?
It will be interesting to see how they deal with the sensor, and does the back protrude much (and thus is interchangeable perhaps with other manuf?), or is it integrated, and slim (like the Leica DMR/M8 approach).
Will they keep the Waist level finder with the 645 format? There really hasn't been a popular 645 WLF for some time, altho old Rollei clients love the 6x6 and WLF. These are challenges for the new designers.
Ah, questions, questions. To be answered soon!