I'd love to think that the hybrid viewfinder would help video, but I wonder if it would hurt more than it would help? Any filmmaker would want the camera to be far more mobile than having it perpetually affixed to one's eye, and imagine how hard it would be to keep the camera steady with the viewfinder up to one's face, and change settings at the same time! Granted, it would definitely help those of us who use our cameras as the functional equivalent of a camcorder (I know I do sometimes), but I don't think it'd be a draw for professional videographers, who use external monitors anyway. I still want to see what Canon would do with a hybrid viewfinder though, it sounds fascinating!
the viewfinder definitely helps video. having a third point of contact for handheld video improves stability immensely. just imagine taking a photo by holding the camera out with just your hands, vs the normal way of putting it against your eye. the improvement in stability is the same for video.
even pro videographers need to go handheld sometimes, and a rig is not always an option for doc/event shooters. I would be a lot more interested in the 7D2 with a hybrid viewfinder.