With a 5D Mark III
Whenever we see a new 5D, I’m told we’ll also see it kitted with a new 24-105 f/4L IS II lens.
There has been talk about this in the past, it’s definitely possible. The optics of this lens could be improved, though I think it’s very good. I’d love to see it with the same hood/zoom design of the 24-70.
I have no idea if there’s some kind of design they could come up with to aid video.