6 kinds of Diet Coke

What's up with all the kinds of Diet Coke out now? I went into the convenience store to buy a beverage yesterday, and bought the Diet Coke with Splenda because there was a 30-cent coupon. I made the comment to the clerk that there are "like six kinds of Diet Coke out now." So later I got to thinking and I actually underestimated. I count 7 kinds: Diet Coke, Diet Cokes with lemon, lime, and Splenda, Diet Vanilla Coke, Diet Cherry Coke, and the newest, Coke Zero, which seems to have gone from nonexistent to everywhere in the last week. Can Coke Zero actually be creating a new market? Isn't it just going to draw from the usual Diet Coke (or regular Coke) drinkers? By the way, Coke Zero has the same ingredients as Diet Coke, with the addition of another artificial sweetener, acesulfame potassium, along with the aspartame. I'm drinking one now (59-cents for a 20-oz bottle). It doesn't seem that different from the "original;" perhaps a little sweeter. Things that make you go "Hmmmmm..."