A smoking ban just passed recently here in Ohio, and I can definitely say it's hurt business at the bar I go to most often. It's definitely better for singers (even though I smoke, myself, I can tell the difference in my voice now that I'm not in secondhand smoke all the time, though as a smoker I hate to say it).

I do think the drunks in bars are more of a problem than the smokers. Sounds like the same thing exists in the UK, really--a friend of mine who works at the Waterstones in Winchester told me that, when they had their Harry Potter release party, people from the pubs kept coming in and causing trouble, even though the customers were mostly children who had been allowed to stay up past their bedtime to get a book and a bag of sweets and chosen for a Hogwarts house. Not that I think much of Harry Potter, but these were kids holding their mother's hands, and they didn't deserve to have their evening disrupted by loud, rude, foul-mouthed drunks fresh from a night at the pub. A person is much more likely to get into a fight or cause trouble after drinking than they are after smoking, not that I have a problem with either in moderation.