Originally posted by Philippos Personally, I doubt Leica's move will be any succesfull at all
I share your doubt. Maybe, for a different reason, though.
I have trouble to see that the market will eventually accept all possible sensor sizes. Photographers will have too much trouble to use them all. Just like film only existed in linear sizes stepped at least 100% apart (Pocket, 35mm, MF).
For this reason, I only see a few discrete sizes to stay (diagonals in mm given):
P&S (~10; 7.5 - 9.5)
FT, mFT (22)
35mm FF (43)
MF (75)
IMHO, intermediate formats will eventually most likely die out. Because they sit in niches which aren't protected. This includes APS-C (28mm diagonal [K20D]) and the new Leica Pro format (30x45mm, 54mm diagonal). Surely, the Leica Pro format has better chances to stay than an APS-C-sensor/FF-bajonett combination...