I don't really have a horse in the race. I probably spend an average of two to three minutes per day in the hallway, and while it certainly smells like cigarette smoke I don't find it overpowering. It's vaguely annoying, and I'd be a bit happier if it didn't smell like smoke, but not by that much. I don't smell it in my unit.
Several of the neighbors are upset about it, though, and want something done. My intuition is that they're overreacting. There's an argument that could be made about property values, but I think it's a pretty thin one and probably not terribly credible. I could probably find some rule in the bylaws that he's technically in violation of, but it would take a slightly liberal reading of them.
Changing the HOA bylaws is far more difficult than it seems like it should be, and is probably overkill. We've done it once in the seven years that I've been here, and that was to solve a *much* bigger problem.
I'm glad that the general consensus was in the vicinity of "do nothing".