Actually, "old" Diet Coke is still as it was. They just have a version that has Splenda as one of the sweeteners. The colors on the can include yellow (I assume to equate to the yellow packets.) Coke Zero is sweetened mostly (or all, I do not recall which) with acesulfame potassium. My take on it is that it is essentially Coke Light available outside the US (drinkable, but not great). DC with Splenda is also nothing great. ILuvParis started a thread a month or so ago about this. His take (and I agree) is that while both Diet Coke and Splenda are good, Diet Coke with Splenda is not. It all is a matter of individual tastes. I still prefer basic Diet Coke with apartame over any of the other variations. But I will take any DC variation before any Diet Pepsi version.