I would wonder if the 7DII would maybe then be a full frame camera at 18mpx?
I'm usually wrong on this stuff, but I really don't understand why Canon would want to put out a "cheap" full frame camera. Even though there had been much griping about the price of the 5DIII, it's spent a lot of time back-ordered at many shops. Why cannibalize sales on a big seller with a cheaper model?
As another has alluded to, I also don't see why they would want to continue to have three tiers of APS-C camera (Rebel, XXD, and XD). I would look for "70D" to take over as the mid-range prosumer model, hopefully restoring the more solid build quality and feel that was compromised in the shift from 50D to 60D. Then (and here's me starting to wish) I'd like to see the 7D market space filled with an APS-H camera. I'd hate to see APS-H end with the 1D MkIV. APS-H doesn't match full-frame for shallow DOF effects, but it is a nice upgrade from APS-C in this area and it gives a little more reach with tele lenses than FF.
Good points, all. Though, does anyone know the real sales numbers of 5DIIIs? My local shop was talking about this the other day. They get 2-3 shipped to them a month, and sell that many easily. But they aren't selling tons and tons of them. Leaves the question open whether the supply problem is really one of demand, or one created by Canon due to the very metered release of units.
The lower cost full frame would be a seller, so I can see room for it. The 5dII still sells, so would a replacement at the same price point. It doesn't cannibalize as many sales of the 5DIII as you'd think - its people who can't afford or justify the cost of the 5DIII but still want FF performance who buy this camera (small studios, avid consumers?).
It'll be very interesting to see what comes of these seires of rumors. It'll tell what Canon is thinking.