I worry about this too. I'm 26 and my surgeon said that exercise will help, but because I'm so young, I have plenty of collagen in my skin that I shouldn't worry too much about excess skin. The good thing, if it happens you can always have it removed.
If you're like me, I think "G-d, I hope it doesn't happen because I really don't want another surgery", but at least the medicine, science, and experts exist to correct the problem, should it occur.
I'm in the same boat. I'm so hungry and I'm already sick of my allowed foods. I had the surgery almost two weeks ago and as for right now I regret ever deciding to do this. Weight Watchers was hard, but I could still eat and not have discomfort, or feel like I'm going to be sick if I take six bites of food instead of five. I'm just really low right now and can't wait to see my psychiatrist on Monday. I just wish that everything was an instant fix; like the surgery would just take away my cravings and that I would just be content with 5 oz. of liquids every three hours. I hate that my entire life (for the rest of my life) will be a constant reminder that I can't eat food like I use too and its depressing me. I just want to feel normal, and maybe in six week I will, but for now, I just want to take a giant sleeping pill that reverses time and that would allow me to know exactly what I'm getting into and the psychological ramifications.