Interesting question. A lot of women seem to normally want to wear a bra so they have the support. I even know one woman who wears a bra to sleep in.
I think the issue should really be what makes you comfortable. Say you were a nudist around the house. You meet a guy and start dating. You might start with being dressed around him, but eventually you're going to want to go back to not wearing clothing. So you tell him you're a nudist. He can either dump you, accept it, or be indifferent. What you want is the guys that's OK with it or indifferent. As long as what you're doing is comfortable for you and not something illegal, then the only thing the guy's opinion means is if you keep dating him or not. As you can see from the responses there are guys that would and guys that wouldn't like it.
I myself feel a woman should wear what she likes and is comfortable wearing. That's what I do. I'm the one wearing my clothing, so shouldn't I like what I'm wearing or not wearing?
I think the only thing you should consider is when you start doing it. If you do it too early in a relationship you might send the wrong message. Remember guys think with the little head a lot, and if the guy can tell you're not wearing a bra his brain functions might switch over to the little head.