I have got some new information about Canon’s murmured upcoming medium format DSLR, said to be announced at Photokina in September. My source told me that the camera will have an EF mount but may not be named EOS. Moreover, the medium format DSLR could possibly not accept all of the EF lenses, due to focal length issues. In other words: newer EF lenses will be supported and (older) lenses with popular focal lengths that actually are suited for full frame sensors will see new editions for the medium format camera (possibly in Spring 2013). Since an EF mount accepts all EF lenses, the only way I can figure out you can block certain EF lenses from being used is through electronic sensing (my speculation). It is not known if the medium format DSLR will have a mechanical interlock for EF-S lenses (though I think this is more than plausible).
Finally, the same source told me that Canon could not announce a more pro oriented mirrorless system camera in Fall (Photokina), leveraging first the recently announced EOS M.
That’s all folks. Let me know your thoughts.