My small, modest wish list:
0) I want a touch screen that lets me choose AF point with my thumb while I'm looking through the viewfinder, just like the M5. If the 5D5 gave me JUST this, I'd upgrade. Yes, I understand this is essentially a mirrorless feature, and I'm OK with that.
1) That it come in 2020, which would be a reasonable yet slow release schedule for evolving technology
2) 10+ fps
3) Better tracking of small objects in frame. As it is now, no matter my settings, I can't get a Canon camera to really lock on an object once it hits a busy background. I think this is partly because the objects I'm tracking are rather small in the frame (usually about the size of a single AF point as it is displayed in the viewfinder)
4) Auto AFMA. This was brought home to me when Canon CPS sent me back my repaired (for free, post warrantee) 5D4 and I had to do it all over again as it had been reset
5) 38-45 mp *or* a 1/2 stop improvement in high ISO IQ in low light, or some compromise of both benefits to a proportional, smaller degree.
6) Even if it does come with a mirror (don't care either way), I'd like an EVF that allows focus peaking, zebras, yada yada
7) An intervalometer feature that wasn't programmed by a third grade class. It would be a couple hundred lines of code to give us features like bramping, multiple schedules to save battery, etc. It's not like Canon's own crazy expensive hardware intervalometer has these anyway, so it's not like this would add to any sales cannibalization.
8) Stop being hinky about the interface to outside controllers via the USB port so that applications like FOCAL can fully automate its AFMA process, etc. More interoperability is a good thing for everyone.
9) Make Dual Pixel stuff useful. In the least, grab the extra stop of DR by employing the extra data. Another must: give an option for the DPRaw format to be translated in camera to a normal raw. Making necessary the use of Canon's own image software on the computer is death to any feature, no matter how cool.
10) Add the dimension of distance to subject in AFMA process, like Tamron and Sigma do. Ok, don't do that if you don't automate AFMA, but if you're going to automate AFMA, this would be enormously desirable, making some meh lenses into peaches.
11) Persistent auto connect to Canon's own Ivy printers, designated mobile devices, etc. It is not at all reasonable to expect people to manually reconnect every time a device sleeps, etc. I don't care if it's bluetooth, NFC, wifi or telepathy. Just make it persistent. As part of that, provide a mode for auto-offloading of RAWs during a shoot, even if bandwidth makes it take a while to catch up.
12) Integration with Lightroom Classic and Lightroom Mobile. I want my phone to be an automatic conduit to my library at home.
13) Dual CFast (necessary with 10x60mb files per second)
14) A buffer that will take at least 20 seconds of maximum FPS in RAW. That translates (given suggested FPS and MP ratings) to about 12gb of cache, assuming only half of amount is needed in hardware, as the time to fill the cache once will be the time needed to free 50 percent of it, etc.
15) A leap. Something. Surprise me. Make it so that we nod and say, yes, Canon still puts out a camera better than all others, at least for a brief time before it is overtaken by an overly-long development cycle.
I'm pretty confident other vendors will be offering equivalents to most of these things, even though some are unlikely for all vendors (Lightroom integration). Dual pixel stuff would of course just be available to Canon. As it is now, the D850 offers almost half of the above. I don't think that Canon can do one of those "all new" sensors with the same megapixels, +1 fps, add a new button and add three software features and call it a major release that keeps the 5 series in the same class as the Nikon D8xx series for the Sony A7R series. To do that sort of upgrade would degrade its class.
