I think Canon should release 70D with the new fab sensor, WITHOUT telling anyone that it is new. Just to test the waters. (probably not possible, as people will dissect the camera anyway). But if they released it as 18 mp, swivel touch screen, AFMA, WiFi/GPS etc, they could try to pass it as the 650D sensor...claiming new algorithms or whatnot that explains the better DR/ISO.
Then the 7D mk2 comes along with the new sensor, more MP and trumpets! (well, one can imagine)
Well, in my opinion, 70D should go back to 30/40/50D format (no swivel screen, and reintroduce magnesium build and AFMA. WiFi/GPS would be nice too). Basically be a 7D classic, but new. (like the 6D is for 5D mk2)
The 70D will definitely be torn apart considering how long it took to come to market. iFixit, Chipworks, Roger Clark, DXOMark, etc..
I think that the future X0D line will all be tilt/swivel screens. They're not fully weather sealed, so there's no need to have it flat to the back like the pro cameras. The demographic it's for are enthusiasts, but will want consumer features like tilt/swivel for video & touchscreen for ease of use.