CanonRumors reports that two Canon prosumer mirrorless full frame cameras are currently in development. The new flagship mirrorless camera is rumored to be announced first and 6 to 8 months later the lower-end model will be introduced. It is still not clear what lens mount will be deployed with the new Canon mirrorless system:
The same source has also told us that Canon has a “a really nice solution for EF lenses on the full frame mirrorless body”, which doesn’t sound like a native EF mount is coming. That said, we’ve heard other people say a similar thing about EF lenses on the full frame mirrorless camera, but no one has come out and confirmed whether or not the body will be EF mount or something else.
Via Canon Rumors