If this camera is better than the 5D Mk3, then it will cost more than the 5D Mk3.
By the way, why would Canon create a camera thats a huge leap from the 5D Mk3, when the 5D Mk3 was released last year?
Also, back to pricing... why would they create a cheaper APS-C camera with better specs than the 5D Mk3? If you were a business man... and this is your business, would you think that this is a smart maneuver? Losing potential customers of FF?
If Canon EVER came up with a sensor that allowed an APS-C to be a HUGE LEAP from their newest FF, then they would shut down everything else and start building new FF cameras, buyers remorse of 1Dx and 5DIII owners be damned. And Canon engineers would be booking flights to Stockholm, and Nikon and Leica will focus solely on microscopy and I'd be selling everything to buy Canon shares!
None of the above is happening right now, so relax. Hopefully the new sensor will be sufficient to improve APS-C performance by 1-2 stops. That's all. FF will still rule IQ, sensitivity, etc. and no one who can afford an equivalent FF setup (that means appropriate super-telephotos for those who will immediately start clamoring about the APS-C "reach") will buy APS-C.
Canon may attempt to impress us with some new solutions, but as long as they stay behind with theirs old sensor technology it is mostly cosmetic solutions compared to Sony/Aptina/Panasonic and others
I think the thread started with rumors about a new sensor technology in the 7DII. Either you believe it (and stop complaining about old sensor technology) or don't (since it's only a rumor) and move on with life (outside a rumor website).