MarkDS and jani,
your observations on the 20D (and comparisons to the 1DII) make me wonder how good a successor could be that is at "EOS-3" or better level on the non-digital side. Meaning using the same EF-S lens mount and "1.6x" sensor size, but with a viewfinder with a larger image size and 100% coverage, more rugged construction, and such. The price difference on the non-digital parts might be under US$1,000, comparing film body prices: wouldn't such an option be appealing at under $2,500? In other words, leveraging the far high production volume and other economies of the mainstream sensor size.
Such a camera might be an easy sell to me.
But I'd like to add a couple of extra points to the wish list (before it's sent to Canon), some of which have been noted in other threads:1) User interface
As the camera complexity grows, so does the user interface. Controls are becoming cumbersome, and buttons are either all over the place, too small, or protruding in an annoying manner. And please make it easier for me to change e.g. ISO sensitivity with mittens on.2) More customizable controls, more stored preferences
The degree of customization in today's camera controls is so eighties-like. No, wait, in the eighties, they knew how to do it, it's later that we forgot. I'm willing to accept going through a bunch of menus to set up controls - once per setup. And let me store a dozen different setups if I want to.
I'm way too tired of forgetting to turn mirror lock-up off.3) Built-in level
Because it can be done. Electronic view or an actual down-to-earth bubble level, anything's an improvement.4) Choice of cryptographic protection of images
A cryptographic co-processor that allows the camera to write only encrypted data to storage if I want it to
, for those precious or sensitive data that only you want. Use GPG (that nice brother of PGP) or some other public key crypto to solve this.5) Self-cleaning sensor
A sensor that's at least partially self-cleaning, e.g. by using ultrasonic sound waves, preferably not of the kind that would disturb bats. 6) Easy cleaning of sensor
Accessing the sensor on my 20D is a royal PITA.7) Replacable sensor
Seriously, why do we figure it's okay to shell out more money on a DSLR body these days than on a pro-level film body? And that's not even for the pro-level DSLRs! This also combines well with point 2 above. Serious disadvantage: controls must be redesigned. While we're day-dreaming: upgradable image processor and buffer memory, too. Removable/replacable non-visible light filter
Taking pictures of males or females in light clothing isn't the only use for IR photography. It would also be cool if the choice of removing the bayer filter (or substituting a custom filter) was there, too, but that would probably be even less practical. But consider the extra opportunities in selling extra gadgetry, Canon!9) Multi-sequence exposure bracketing
Why only three? Why not e.g. "From -6 to +6, in 1-stop intervals"? 2/3-stop, 1/2-stop and 1/3-stop optional. That's two different settings only.10) Give me my DEPTH mode back.
Feel free to keep A-DEPTH along for the ride, I don't care.11) Persistent in-camera buffer
How about an in-camera buffer that can buffer pictures while the memory card isn't in the camera, until the buffer is full? 5 RAW shots are better than 0 (but I hope you'll double the buffer size).12) Open RAW format
Please.13) Open firmware
Let people introduce their own bugs, eh, features, too. Not a high priority, but definitely a cool thing. This could increase sales among nerds and geeks. You know, people who happily spend thousands of dollars on a piece of equipment because of the technical coolness factor. Market it as "Personalized EOS Digital" or somesuch. 14) Viewfinder information
Hey, Canon, look at your competition for a second. Nikon has taken some hints, such as displaying the chosen ISO level.15) A rear LCD status monitor
The 350D has it, the Nikon D2X has it. But there's no need to drop the top LCD status monitor.16) Connectivity
WLAN/WiFi might just as well be built-in, just don't forget the security features.
High-speed FireWire wouldn't hurt alongside regular maximum speed USB 2.0.
It would be really nice if the camera could utilize an external storage device (tethered, bluetooth, WLAN-based or whatever).
Ditto for GPS, it doesn't have to be built-in.
These peripherals pose a sales opportunity for Canon. Hey, maybe you guys could make a really small portable printer, so that we could do "polaroids" if we're on e.g. a street photography rampage. It could be a friendly gesture to the subject, hmm?17) ISO sensitivity
Given how good ISO 3200 looks on the 20D, I'd be willing to accept the compromise of ISO 6400, if it were available.18) Noise reduction
Could I please be allowed to choose different noise reduction settings, more or less aggressive, two or three different algorithms perhaps?
And while you're at it, check to see if the sensor is sufficiently protected against electronic noise from other parts of the camera or external sources.19) Vertical grip
If you do make it optional as on the 20D, in order to cater for different markets, please don't make it both a) too expensive too shoddy, as is the case today. You're losing money.20) Exchangable grip
Come on, not everybody's hands are the same. You had this for the 650 back in '87, why not now? This can be outside the environmental seals, too.21) Look to your competitors
I know I've mentioned Nikon earlier, but there are others with excellent ideas in terms of features, usability and what have you. Learn, adapt, license technology if you have to.
And to Canon's competitors: give'm a good run for the money. If your cameras are lacking in any of the above points, and you think you can implement them easily enough, some of them make for excellent selling points versus Canon.