A co-worker and I were just discussing this earlier this week. We go to Mississippi casinos 3 or 4 times a year and we've noticed that although many of them do have a non-smoking section (Isle of Capri in Biloxi is the specific casino we were discussing), there is hardly ever anyone in them. My co-worker, who is a non-smoker, said that she just never seems to win in the non-smoking area and that other non-smokers have told her the same thing. So they only retreat to that area when they need a break from the smoke.
As a smoker, I wouldn't spend much time inside if I had to take a break to go outside every time I wanted a cigarette. I love going to the casinos, but I know of enough private poker games that I would survive without going to the casino if they went non-smoking. I already play in a regular game at least once a week and a tournament once a month. I can lose my money anywhere!
Casinos typically have very high ceilings and are extremely well ventilated. As a smoker, I wish they would all have non-smoking areas, so that everyone could be happy. The truth is though, that I am well aware that many non-smokers will never be happy with that compromise.