My understanding is:

* iTunes has “parental controls” on music and video content (allowing them to not sell “rated” content to minors);

* The App Store (different to iTunes) does not have “parental controls” hence zero tolerance to selling content that may offend minors;

but-

* OS3.0 brings with it “increased parental controls”
which I’m hoping allows *all* content to be optionally rated: see press release here:
http://www.apple.com/pr/library/2009/03/17iphone.html
which talks about, as a new feature of 3.0,
“parental controls for TV shows, movies and apps from the App Store”

If anyone has definitive answers, I’d like to know (and am also pursuing apple myself).

Cheers!

Reznor has famously refused to produce clean versions of NIN albums for sale in Wal-Mart as a matter of principle (though did release censored versions of songs for radio airplay).

Principle, huh? That’s not the word we use in these parts.