I think that I hate the term "nanny state," but this proposal fits that bill. I further believe that unless the measure affects all establishments selling big tubs of soda (such as convenience stores - not affected by the proposed "ban"), it's unfair and very suspect right from the start. Are 7-11's Big Gulps more healthy than a similar-sized soda at a movie theater?
The bottom line is that anyone with even half a brain knows that sugary soda is an unhealthy drink. They also know that drinking more of it worse than drinking a little of it. If, knowing that, they decide to drink 32 ounces of it on a regular basis, that's their business and not that of the Mayor of New York or even the Department of Health. They can force businesses to use warning labels on large cups (I'm very cool with this), they can probably levy extra "sin" taxes on them (I can't think of a reason to be against this, though I do drink soda), but banning them seems way out of line to me.