According to latest rumors Canon is seeking advice from professional photographers about a medium format system, the question are related to image quality, usage scenarios and type of lens requirements.
We have already published a rumor a long ago that Nikon is also preparing to announce medium format camera (see here), Nikon may announce its medium camera with bunch of new lenses and Sony 50 Megapixel medium format Sensor and Sony is also rumored to announce a compact RX style Medium format camera with 50 MP sensor during Photokina.
Also see our previous rumors – More Canon Medium Format Rumor