Although i agree with everyone here who is saying we shouldn't be so concerned about kids seeing nakedness in changerooms, I can't help but feel a little symapthy for the OP.
He's clearly talkng about those one or two people(for me it's women as i am a woman, but i'm sure men do it too) that seem to be in every change room everywhere. You know the ones, more than just geting changed, they seem to use the fact that everyone is getting changed to be as naked as possible for as long as possible.
Is it normal for people to be naked in a public change room? - Yes.
Is it normal for someone to wander around and have conversations and generally act as though they are in thier own living rooms while remaining naked? - NO.
Are we as a society too hung up about naked bodies? - Yes, but that still doesn't make a changeroom = a nudist colony.
I don't see it as an issue for kids at all, but for everyone. Once you have taken your wet/sweaty clothes off and had your shower, IT IS TIME TO PUT YOUR CLOTHES BACK ON! I don't care if you have to get naked to do what you need to do, but there is a point where you have crossed the line between getting changed and showing off. I'm not sure exactly where the line is, but if you are standing naked in front of me for no other reason than conversation, you have officially crossed it.