The 7D will always remain a crossover body from the pro-sumer to the pro line. Also, as neuroanatomist so eloquently stated, the crop factor of a 7D body gives your lenses extra reach. This makes the 7D body dual purpose, and a great supplement to a full frame body like the 5D; it expands your creative possibilities.
That said, I'd like the 7D to stay APS-C crop.
So what is the upgrade path from the 7D then? Previously the 1.3 crop 1D4 which meant you didn't lose all the 'crop reach' which all the 7D fans seem to love. Is it the ff 1DX which means you lose all the 'crop reach'. Wont you be upset with nowhere to go from the noisy prosumer body?
I think it would remain the same... the upgrade path from the 7D would be the 5D or 1D. I almost see the xxD line being eliminated. The T3i and 60D are very close in price, with no huge difference in feature set. The two lines are almost identical. Also, Canon took a lot of crap for the changes they made from the 50D to the 60D bodies, such as going from magnesium-alloy to a plastic body and adding that tilt-swivel LCD. Many saw the 60D as a downgrade from the 40D and 50D models, at least with respect to being "semi-pro" versus "enthusiast" type camera bodies.
That said, if the xxD line is eliminated, the T3i, T4i, etc. may become Canon's new baseline standard for the "enthusiast" market. The plastic bodies, tilt-swivel LCDs, and marketing focus towards video will remain. Then, the 7D, 6D (if it ever comes to fruition), etc. series will bridge the "semi-pro" gap to the 5D and 1D "pro" series. The words in quotes are my own definitions for the sake of breaking down Canon's markets.
And, for what it's worth, this is all based on assumption from my own personal "vibe" of the Canon's development progress, and tidbits I get from place like CanonRumors and other sources on the internet.