What do we want as videographers? For Canon to give us a successor to the 5D system we heavily invested in, with similar capability to the market, that's it.
We need a 5D that shoots better video quality than the MKIII and similar resolution to A7s/GH4 but with the Canon colours and overall ecosystem. A few video oriented features after resolution/IQ are mandatory, thing to help us focus (peaking for manual and DPAF for auto), to help us get exposure, zebras/waveform/RGB Histogram in video mode, intervalometer for timelapse, a Flat LOG profile (C-Log), clean HDMI uncompressed out...
these are all features given by the competition so unless they abandon the DSLR-Video movement they'll be forced to give them too. No question. Either in a MKIV or a 5Dc.
The 1Dc is already the best image out there in any DSLR/Mirrorless, just unrivaled resolution, colours, codec, DR, lowlight, filmic organic C-LOG, C300-identical s35 mode, so make that image into a 5D size body with these small firmware features and it will take the market by storm.
A flip-out LCD would be wanted by us, but we'd respect that one downside if it's for photographers' 5D robustness (trust me the 5D/7D is MUCH stronger than all the flip-out cameras out-there like the a7rII, GH4, so there is currently a correlation, don't be fooled into evaluating a cameras rigidty by the word weather-sealed in the spec-sheet, but hey, I'd love it if Canon could maintain the 7D/5D strength and implement a movable LCD, perhaps an only-tilt one is a good compromise between the reliance on the tiny hinge and full body integration, anyway I'd respect as videographer if it doesn't have it in a photography-oriented 5DIV, on a 5DC, no I wouldn't respect it)