So I decided to check it out. I don't drink soda anymore, and this hasn't changed my mind (I mostly drink water for health reasons).
Those saying this doesn't taste like diet are absolutely crazy. From the very first instant it touches your tongue it SCREAMS aspertame (both my wife and I agree). Where it does better is completely removing the after taste which is by far the worst part of aspertame. So instead of a horrible artificial sweetener taste in my mouth for minutes after each sip, it's replaced with a very even, if a little flat, taste.
I tried it both warm and cold, and of the two it tastes better warm... but warm soda isn't very appealing in general.
I will not seek out this as a regular drink because as I said above, I gave up soda a couple years ago. That said, when the desire does strike as it sometimes does, I wouldn't be against having a glass of this versus zero and definitely miles ahead of diet.