I just cannot comprehend any of this. Why do you want APS-H again? >_>
And if a new 7D-esque body gets APS-H, it will NOT be called 7D MKII ... It will have a different series name.
Indeed I'm not really seeing why people think Canon are likely to radically change the position of the existing 7D and xxD lines in the market rather than introduce a new line.
You look at their previous DSLR history and it seems much more likely that a new higher end line will be introduced which makes marketing sense. Why market the previously enthusiast xxD brand as a semi pro camera to reaplace the 7D? why market the semi pro 7D brand to replace the pro 1D brand?
I think you are right - the 70D will be as good as the 7D today - so what happens to the 7D? Perhaps they will drop it and make a 3d/6d semi pro sports range with a larger sensor with 18-24mps and top iso performance and 8fps.
Sensors are one area where size does count. There is a finite (financial) limit to how much you can use technology to squeeze out of a fixed size sensor, When it costs more to produce a little one instead of a better, lower tech, big one then the big one will win. PCs give us the clue - the processing power from a single processor has barely increased in the last 5 years - so they have switched to multi cores to provide the extra processing power. The NEX7 may have more mps but the IQ and iso performance is not significantly better.
The argument that higher density APS-C sensors gives better IQ is not born out in practice - look to the 1DX, 5D (and dare I say it - 12mp ff Nikons) are examples where low density sensors give significantly better IQ than high density APS-C - and probably still do today.
As I said I think its more likely that they'd keep the 7D line and drop the xxD line while introducing a new ASPH line(3D?). The 7D right now is a much stronger brand than the 70D would be so I'd say it would make sense to keep it around even if its downgraded a little(or more likely stays still).
Now there is a thought! If mirrorless CSC cameras take over the bottem end SLR market with M4/3 and APS-C sensors, as some seem to think they might, it would be an exciting (if very bold) move.
This seems like the most likely way ASPH could be used to me, it would give a Canon mirrorless a boost in IQ/DOF over its ASPC rivals and seperate it from the G1X without pushing the price too high. The main probablem with ASPH on SLR's would also be gotten round(no lenses with focal lenghts/image circles aimed specifically towards it) since any mirrorless system would have a new range of lenses created for it.