Exactly, new etiquette. Don't post things to a persons wall that are best said in a private message. don't post embarrassing pictures of yourself or others etc...
My friend just made up a different profile, and only invited some of her friends.
Facebook is modeled after a very childish model of "I'll just share everything with the world". But now you have everyone from future mates to HR departments checking people's profiles and under that scrutiny the current model doesn't stand up well.
You want to invent a Facebook killer all you need to do is figure out a way for people to share everything they do on Facebook while only giving select "friends" access on an item by item basis.