The camera will have dual memory card slots, CF and SD. Retaining CF is a big deal and will make a lot of people happy.
How likely is this to actually happen? The 1D and 5D lines are the only ones to have dual card slots. Even the 6D uses just SD cards, which I can't stand due to how slow and flimsy they are.
I've got a 7D and 50D, and will probably replace the 50D with a 7D2 when it arrives. I'm also getting tight on CF card space, and would like to buy a new 32GB CF card before a trip in a few weeks... but not if it'll be obsolete with the new 7D2. I was really hoping we'd have a more concrete announcement by now.
Given than the 6D now uses SD cards, how likely is it that the 7D2 will use CF cards? Will they abandon the 7D1 users and cater to those upgrading from consumer bodies by using SD cards? I'm sure speed is also a consideration, since that will be a big selling point of the 7D2 over the 70D or 6D.
The choice between using CF or SD cards will be determined not only by how much this rumored camera will be positioned for professional users, but the maturity of SD cards as determined by Canon. If this camera will indeed get CF and SD card slots, this will make it comparable to 5D Mark III, which I don't expect it will be. So in my opinion this CR1 rumor is not likely to become a reality, because as you stated the 6D uses just SD cards, so the 7D will likely share that trait, if it is considered as being somewhat restricted in comparison to a 5D Mark III. This logic may not be found appealing by many, but Canon may nevertheless use such kind of a distinction in card support.