Interesting that with all the things that we attach to camera bodies ie., flashes, pocket wizards, flash brackets, PC flash cords, grips, black boxes, tuxedos, cp-e3's, that a company has not come out with a CF card that ribbon cables to larger storage device of some sort.
Could be something simple like a CF card stack putting 6 CF cards is the space of a single D cell battery. Such a device could even mount to the bottom of your grip. Fill one CF card, automatically start filling the next, etc...
Could be complex. Same ribbon cable idea connecting to a portable hard drive. Pick your size, 100, 200, 500 gb..., but then again that's putting your faith in only one device again isn't it?