Considering it is long overdue, I would expect this to be the high-mp body, the successor to the 5dsr, not because of demand, but because it is overdue. Also a high megapixel count REALLY turns heads in this market (when admittedly there is a lot more at play than high MP, including ISO quality, buffer speed, pixel density issues, overheating, and burst speeds.) After owning a 5DSR, and dealing with its cons as a commercial shooter, I will pass on a high-mp body. BUT: I would love to see any Canon body with a BSI sensor or a variable low-pass filter. The Sony RX1Rm2 almost won me over to them, except that the RX1 camera is a sealed compact that isn't weather-sealed. Also, Sony is not a camera company, they are a consumer product company, and maybe worst of all, their interchangeable lens full frame mount is too tiny, built for a DSLR APS-C, not specifically a back-focused mirrorless full frame. (It would be like if Canon had designed the RF full frame mount around M or EFS lenses. Because of the massive RF mount size, Canon will always rule the day with glass when compared to the dinky E-mount.)
Besides a 5DSr equivalent (R5SR?), it could also be an aps-c RF body in line with a 7d. I have no clue why people want a prosumer aps-C that is the same body size as a r5, it makes no sense to me, but people sure seem to want that big body with the tiny sensor. That can't be about price any longer since the wonderful RP is only a grand.
I am excited about the photo future. Sony is making great innovations, and Canon needs that to stay up-to-date, since all Nikon has done since 1987 is play catch-up with the hallowed EOS lens system. Canon should be worried still about Sony, yep, but they should also just ignore clueless Nikon, who have moved their manufacturing to cheapo land as they begin what I think is a death spiral of irrelevance. In my worthless opinion, the entire market depends on glass and the mount size, followed by bodies and features and lastly, sensors.
Hope this isn't too troll-ish.