I could see topless, but that would pretty much automatically leave out anyone with implants... Which in and of itself may not be all that bad an idea. Some 'bolt-ons' are large enough to actually obscure pec development..
Having said that, let me now go back on myself and say that while there are examples of women whom I admire who do not fit into what I am about to say, overall I prefer female bodybuilders to be just that. Female first, then a bodybuilder. As stated by me elsewhere, I don't have much interest in the utlra-dry, transparent skin, sunken eyed, 'contest-ready' look that some favor. I'd really like to see the competition place some reasonable emphasis on reality (what a concept!) and give credit for overall aestheticism as part of the scoring. And before anyone goes off on me for saying women should be judged differently from men, let me add that I say that we need some similar sanity in men's bodybuilding, too.
We (collectively) seem to be at the point where winning at any cost is the thing. Another poster pointed out in a different thread a while back the high mortality rate among bodybuilders in general who do very real damage to themselves in their quest to "be the best". It seems to me that one of the things we all need to be the best at is taking care of ourselves, but somewhere along the way, we lost that concept. I think it's time to try and get it back.
End rant. For now, at least