This blog post is very helpful. (via 43 Folders) It explains why I like Coke Zero better than the original Diet Coke, which I have been slavishly devoted to lo these twenty some-odd years since Diet Coke hit the machines on the UT Austin campus.
In a nutshell, Diet Coke was the sugar free version of the formula for the New Coke debacle. Coke Zero is the sugar free version of Coca-Cola Classic. Explains a lot.