I, and many people I know, would play at the Casino that did NOT allow smoking ... I don't smoke and really dislike the smell. I don't know if it's still the case, but I remember hearing about an entire non-smoking casino (or at least building of a casino) in Laughlin, NV (near Las Vegas). When I was in Detroit a few years ago the MGM Grand had a non-smoking floor, and some casinos have sizable non-smoking sections (sometimes closed off) that get plenty of action.

I think there's definitely room in Las Vegas and Reno for at least a couple non-smoking casinos, and I heard recently that Atlantic City is contemplating a law to make all (or at least most?) of them non-smoking.

--Havspace