Okay, time to have a little fun and predict the future. Check back in 2011 or 2012 and see how close I come.
Sensor somewhere in the 50-100mp range. (Not that difficult since Canon has already unveiled a 120mp APS-H sensor.)
Flexible scaling of file size for both RAW and JPEG files, allowing photographer to adjust resolution depending on shooting conditions and needs. (Already available in limited form as small-RAW, small-JPEG, large-JPEG, etc, just more choices and more resolution.)
Digital zoom function that allows photographer to select full frame, 1.3x crop, 1.6x crop, 2x and maybe even 3x or 4x. 100 mp sensor means no appreciable loss in quality, so the photographer can use a 300mm f2.8 lens as a 600mm or 900mm if needed for sports or wildlife shooting. (Canon has been upgrading their L Series lenses to meet the demands of the next generation of high resolution sensors)
Dual card slots, but also can be tethered to an external hard drive, so photographer can wear a portable terabyte hard drive on his belt to store image files while shooting. (Modern-day equivalent of bulk film backs.)
Will NOT have a modular back to change sensors. (Canon has built their reputation on sport and nature photography under extreme conditions. A modular camera just makes weather sealing more difficult and increases the odds of failure. The last thing they want is for the back to leak in the middle of the rain forest. Besides, with a 100 mp sensor, there is no need to switch backs.)
"Modular" may refer to some optional accessories for video use. Not sure, but it will probably have some special features or options available for video. I know nothing about video, so I'll leave that to someone else.
Everything I've identified is already available or under development, so it's all very do-able, but also would cement Canon's position at the head of the technology wars if they put it all together.
That's my prediction. Anyone else want to venture a guess.