No idea why some of you are even saying "that would be very confusing" with very bolded. If the stuff we`ve heard is correct (the new naming for the Radeon 6xxx series), its really no different than stopping a series name, and starting a new one. At one point 9700 was ATIs top card.
Unless you are old and dement, its really easy and goes like this:
Id myself prefer if there was a 3 number (xxx) difference between them, As it would mean sticking to their current system. But if they are changing it, it doesnt make it any harder than what ive written in the quote.
If the naming scheme changes, Im sure AMD will include in their reviewers guide, if such a thing exists
EDIT: IF there is a change.