I was discussing this a few months ago on this forum and was basically shot down...
It would be great to have a medium format canon series. Yes it would probably just be for professionals and no you don't need the extra pixels for weddings/sports/birds in flight. I know I need them for larger billboards in airports or down the sides of buildings. A price point around the £8,000 to £12,000 mark would be great as it'll be lower than the hasselblads. an all in 1 system would be great rather than the phase 1/mamiya separates system. I want a massive mirror with a huge loud flop and I want to have the old school look down view finder.
Yes they'd make/design new lenses. But that's what a company does, builds stuff and we buy it if it fits out needs. MF is the new FF and I welcome it's possible return to affordableness.
I think it would take a monumental effort to start from scratch.... Not saying they couldn't, but it would be hard. That's why I see some kind of deal with Hasselbad as a likely sign.
Look at micro four thirds.... Several second tier companies got together, cooperated, and they are now the dominant player in mirror less cameras.... The lenses can go anywhere.... Why not the same for FF?
Think about it.... Canon makes a deal with Hasselbad to share the mount.... Canon makes a medium format body and starts selling it. MF sales jump, Hasselbad bodies might take a drop in sales, but the lens sales would skyrocket.... Both companies make out like bandits....
P.S.... If you carried around a 4X5 camera and a stack of film holders, medium format is tiny.
I see medium format being a little different though, m43 is aimed at a very broad audience and offers a wide range of bodies/lenses to try and maximise this audience, a Canon MF system would likely be aimed much more specifically, you look at Hassleblad, Phase One and Leica and they don't offer anything like the same size of system.
I don't see Canon looking to work directly with any other brand, I'd guess a lot of the reason for producing a MF system in the first place would be linking the brand to ultra high end cameras, If a takeover happened I'd guess we'd see either a total rebranding or staff and facilties put to work creating a new Canon system.
One interesting direction for me would be to take digital medium format mirrorless. In the days of film rangefinders afterall made up a lot more of the MF market than they did the serious 35mm market, I'd guess due to the greater size saving. Besides the price difference I think size is really whats hurting MF today compared to FF DSLR's, my second cousin is a travel photographer just sold off a Hassleblad system in favour of FF DSLR's and size was the main issue for him. Added to that I think the MF market has clearly been targeting rich amateurs for whome size is likely to be an even larger issue.