HU: New cv 12mm M-mount is already for sale on ebay!
Voigtlander Bessa Leica Mount CamerasMade in Japan by Cosina in partnership with Voigtlander, the many modern Voigtlander Leica Screw Mount and Leica M mount bodies offer inexpensive and often unique options into entering the world of Leica rangefinder photography.
Ditto. How difficult is it to "focus" a 12mm on a 35mm camera. The LTM is less expensive AND includes the finder. The only advantage to the new M-mount is it takes filters without an adapter (and you don't need to buy a M-Mount adapter). The optics are the same.