Have you been indoctrinated by those rumour webpages like http://www.canonrumors.com/ or something?
They're not gonna abandon an already winning formula. I really don't understand why you're so adamant that they'll bring out a whole new format and lens system. Contrary to what you might think, it DOES take MASSIVE amounts of research and development to create a whole new imaging format. It's easier and much cheaper to update an existing design in a familiar format than to create whole new camera systems from scratch.
Even if, say Nikon were to bring out a MF format sensor and lens system, it would be very possible that Canon wouldn't even follow as Nikon would be making a product in which canon doesn't directly compete with. Like Nikon doesn't really make photocopiers, and Canon doesn't make eyeglasses.