Canon like Panasonic are rapidly loosing their position when it comes to large sensor cameras, Canon need to pull a 4K/2K recordable Super 35mm camera out of the bag ASAP.
Sony are leaving everyone standing with the F5/55 cameras and the new V2 firmware implementing 240fps slow motion feature in 2K is an even bigger incentive to buy into the Sony F5.
Slow-mo may be a bit of a gimmick but if you have the choice of having it or not having it comparing two similar spec cameras you would choose the camera that had it.
Sonys F55 has internal 4K recording as does the Canon EOS 1Dc , why on earth the C500 never had the facility to capture 4K internally is a mystery to all of us, hence the poor uptake on the C500.
1080 50p is a must for any new line of Canon Cinema cameras as once again Sony have pipped them at the post with most of their Pro line up having 1080 50p, even the NX-30.
XLRs on board the camera is another essential for a new C700s camera as the C300/500 is a mess, as is an adjustable Hi-Res viewfinder like the Alphatron, DPs are getting fed up with cameras that compromise the shoot and there is nothing worse than a crap viewfinder as seen on the C100.
Lastly if Sony can produce a 4:2:2 16bit RAW camera then Canon need to match it !