Interesting thread. As someone who drinks a lot of diet soda, it interests me. My major downfall is the restaurants which offer free refills (did I mention that some also have wi-fi access -- a new pastime for me too.) In any case, I don't think I suffer from any ill effects except probably too much caffeine and bloating, possibly some digestion problems.
At least I don't suffer the odd effects of "Cornholio" (of Beavis & Butthead fame -- google Cornholio to learn more than you wanted to know...). Briefly: Beavis works at a burger joint, and OD's on soda and turns into a lunatic.
But I still drink more soda than I should. Hey, it's free!
I didn't see much mention here about a big-time problem of traditional soda: empty calories. I bet that far more health problems are directly traceable to sugar or the more likely high-fructose corn syrup. Diabetes? Heart Disease? If I drank regular soda like I do diet, I'd probably be getting 500-1000 empty calories per day. Ugh.
I've got nothing against an honest day's work, provided that someone else does it.