The funny thing is that if the mid-range camera offerings were the problem, we all know they could change that in no time (not holding off the last few things you could add).
The problem I see in stills is that the 5D mkiii is perfectly fine for 35mm. Yes, you can increase DR and lowlight, but it doesn't really change anything. 35mm is almost maxed out. So if they add what we are asking for, it's sort of game over.
This is obviously an exageration, but I think there is some truth in it.