Don't you over-complicate things?
The way I see it, they:
a) have three product lines
- the xD-series
- the xxD-series
- the xxxD-series
b) use three sensor sizes
- the full frame (currently 1DS and 5D)
- the APS-H frame (currently 1D)
- the APS-C frame (currently xxD and xxxD)
Wouldn't it be simplest and most elegant to have:
1) FF sized xD-series
2) APS-H sized xxD-series
3) APS-C sized xxxD-series
This way their product line would be easy to understand.
They could also make it very simple for the 1D-series once the APS-H is dropped from the flagship line. There could be top-of-the-line 1DmarkIV full-framer (with built-in battery grip) coupled with physically smaller 5DmarkIII full-framer (without battery grip) and let them be otherwise close to identical in performance. Or in case they need more product variety they could easily have 3D or 7D as long as single digit would mean full-frame sensor. Would be very simple and understandable.
Now the xxD product line, if indeed the 60D would have APS-H frame, it would be insanely great. And they could drop APS-H sized 1D in the next revision. The xxD product line does not have to necessarily have all the goodies, it could very well be slower and whatever, but I'd sure love to see cheaper 1.3 crop sensor. Prosumers would love this step up, and would make Nikon's 1.5 crop look worse on comparable models
And this would effectively mean 1.6 crop sensors are left for entry-level DSLR models (xxxD), which would also make sense because beginners want small equipment that are even a little bit cheaper.
Oh, well -- I guess we can always dream
Maybe I'll just have to buy that 5DmarkII and stop waiting for a miracle.