Zeiss issued a press release for the upcoming 2012 Photokina show. One of the upcoming new product will be a "special surprise" ZM lens (Leica M mount):
"For fans of the Carl Zeiss family of ZM systems for rangefinder cameras, Carl Zeiss has a special surprise in store. In 2013, at least one fast lens with M bayonet will go on sale. Using lenses from the ZM series with adapters is also very popular on mirrorless system cameras."