This rumor comes from the French website lesnumeriques.com claiming that Leica will be releasing a new medium format SLR camera (S3?) during the Photokina 2012 show. The Leica S3 will feature a new medium format CMOS sensor produced by the European semiconductors manufacturer STMicroelectronics (Goole translation):
The adventure picture is likely to continue on Photokina: “a renowned German manufacturer”, Leica, is expected to announce a new SLR camera – medium format? – With a giant sensor, CMOS, signed ST. To be continued …
I’ve heard that the current S2 medium format sensor is no longer in production and this impacts also the Pentax 645 medium format camera. Both sensors were initially produced by Kodak, but then the Image Sensor Solutions (ISS) business was sold to Platinum Equity.