If we assume no sensor improvements, we get the following:
Look at the T4i. You can't pimp it out much more. The only things missing are wireless and GPS. Other than that, it has every function canon has for a camera. If there was a new rebel, you have to add this. This leaves the 70D with the only possible improvements over the new rebel as better build, shoulder display, and the reintroduction of AFMA. Since they said it would be incremental improvement..... No new sensor....
The 7Dii, if it is to better than the 70D, would have to be dual processors for higher fps....plus all the 70D functions except for tilt/swivel screen.
The problem is that I can pick up an Olympus E-M5 that beats the iq of any canon APS-c camera and they are supposed to be introducing an even better successor to the E-5 ..... Or I can go Panasonic......or I can go Sony..... Or I can go Nikon.... Canon is now positioned at the bottom of the APS-c world for iq and even micro four thirds is beating it. A new sensor is long overdue and no upgrade will be worth it until they release one. I just hope they do it before we add iPhone to the list of cameras with better sensors.