Remember when they changed Coke? There was such an uproar they had to offer it again as Coke Classic? Maybe they'll do the same with Pepsi - call it Perpetual Pepsi or some such.
I'm a diet Dr. Pepper fiend, but since I found out that Dr. Thunder is the same thing (and much cheaper) I switched to that. I find that if I'm in a different part of the country my beverage tastes slightly different, possibly because of the water that's used to make it.