Not to trivialize anyones choices or investments I was just highlighting the biggest case representing the most likely IQ fanatics that have a sizable EF-S investment that would be most impacted by a move to FF and that Canon would be the most concerned about in their branding and upgrade paths. What are the EF-S lenses you have?
Well, seeing as how I shoot with BOTH APS-C and FF cameras I see no reason to NOT invest in EF-S lenses, if the need is there.
I love my 5D2 for what it can do and I love my 7D and NOBODY is taking my 7D away! My wife loves her T1i even though she has the 5D2 and 7D to play with. You see, each camera will appeal or not appeal to everyone differently. Just because one person swears by FF cameras, someone out there will disagree and they won't be wrong for doing so!
It's not really an issue to me and as to what lenses I own, that is a different subject that is not part of the 7D2/70D discussion we are having. I simply meant that Canon needs to take into account someone who has bought a APS-C camera and if they make an upgrade to it, it should be compatible with what equipment they already own. (EF, EF-s) Canon has maintained that tradition so far and I believe they will continue to do so with future camera bodies.
If there is a 70D, it WILL be APS-C
If there is a 7D2, it WILL be APS-C
If there is a T5i, it WILL be APS-C
If there is a 5D4, it WILL be FF
Any new cameras that do not conform to the existing formats will simply be named something new. (I.E. 3D, 6D... whatever) Pretty simple really.