Well I have kind of a good (and quick) update to this.
DH admitted that he thought I was making a bit too much of a deal on it last night. Then today, he had to go to someone's house for work, and they smoke. He said it was disgusting. He couldn't wait to get out, and immediately put his jacket in the wash when he got home. Obviously that's someone smoking in their house and it building up. But it was a bit of an eye opener for him.
He's kind of in the same position I am now though. He doesn't know how to best approach the subject, and doesn't want to start any fights. But at the same time knows something has to be said.
Personally, I'm of the opinion that this needs to happen before the baby is born, definitely. But bring it up now? Or wait to closer time? Or...? Obviously first we need to come up with criteria that we're both comfortable with. And that's going to take some talking out for sure. I think as soon as we decide what ground rules we want, we should go ahead and approach the subject with everyone we're normally around who smokes. (Which unfortunately or fortunately depending on how you look at it, is just this one person.) That way when he gets mad, it'll give him some time to get over it before the baby is born. Plus will hopefully keep me away from it as well.