Thins are always scary if we've never done them before. Nearest paralell I have is my first time on a nude beach. In that context, it's not a big deal since everyone's nude. In the context though of a movie set, I'd imagine everyone else will be clothed so can be a lot more uncomfortable. But then acting to me would have me fainting just doing regular lines.
I'd imagine that now, nudity isn't what it was even 20 years ago. Much more cross-over from porn and non-porn film now, and doing nudity in non-porn isn't the sort of thing likely to harm anyone's career when some's careers only exist because of a sex tape or porn.
Nudity's always been part of art including film. If it seems 'right' and non-exploitative, do it. Whole field of acting is basicly just exhibition anyway, whether clothed or not shouldn't matter. You wanted people looking at you and thinking about you by becomming an actor in the first place. Doing a nude scene will have how they think of you change some, but not in a negative sense as with times past. Now it's more likely to be, "She's a professional. Did her job well even nude."