I still believe Leica will announce a new M digital rangefinder camera at the Photokina show in Germany next month (September 20-25) - this has been the case during the past few years. The new M is already being tested in the field and is rumored to have a dedicated ISO-wheel/dial and a slightly bigger LCD screen. This is all the information I have received so far. If you have any other details about the new M, you can contact me anonymously here.
Picture credit: Photokina