As someone who plays live music for a living, I appreciate non-smoking venues very much. I don't think a law needs to be passed, but I wouldn't be against it. I do believe, however, that club owners should re-think the attitude that says "If I don't allow smoking, people won't come" because that's just not true.
Case in point: Organissimo played three gigs last week. On Thursday we had a gig at the New Holland Brew Company in Holland, MI. No smoking. Place was packed. They also have great food and great beer.
On Friday we played Bell's Brewery in Kalamazoo. Again, no smoking inside. They have an outdoors patio where people can smoke. We had a great crowd.
On Saturday we played the Allegan Jazz Festival which was in a 1920's theatre with no smoking. It was fine.
Smoking sucks and it's especially annoying when someone with a gigantic cigar sits right in front of you when you're playing and trying to sing.