We tend to forget here that we are not the target market. We're the sheep who will buy Canon bodies regardless because we already have our lens investment.
Canon need to get a new generation of photographers wanting to use interchangeable lens cameras. And for those who have grown up using their cellphone (or iPad!) to take photos the tiny screen on the back of most cameras is a serious problem.
Add to this the perceived "complexity" of 'serious' cameras. Dials with cryptic codes (Av/Tv, etc) - remember we live in an age where people don't want to read manuals.
So, like it or not, we're going to go towards, at least at the lower end, we have cameras with large touch screens, with the touch screen assisting with things like defining what areas you want in focus or not (rather than manually setting apertures). Our favourite buttons will go because they're confusing and put people off buying a camera.
Improvements in algorithms and the ability to constantly monitor the image data (with a mirrorless or liveview device) will lead to far more intelligent automatic shooting than we've seen before. Better control of levels, better iso management, using some HDR-type techniques with fast multiple frames to get greater dynamic range or greater depth of field automatically, digital effects such as automatic background removal, etc, etc.
And, we'll inevitably see cameras that are not just wifi but cellular enabled too. Want to post your photo immediately to Instagram directly from your camera? No problem.
So, if you're worried about whether your scroll wheel is going to disappear or not I'm afraid you're really not going to like what's coming next...
Jolyon
(on the positive side I don't think this change will filter down to non-rebel type cameras for many many years)