Australia was robbed. While there was no assurance of an Australian victory in extra time (or penalty kicks, should it have gone that far), that was an unjustified PK that decided the game in stoppage time. The Italians have learned the lesson that FIFA have been teaching people by ordering the referees to be so over-sensitive: dive like your lives depend upon it.
I am generally sympathetic to referees, having been an AYSO referee in my teens. (I played for a league-winning team, too, albeit no thanks to me.) But referees have gone overboard in this World Cup, and the players are playing to the referees. That "foul" that let the Italians win should have been a yellow card, all right -- to the Italian player who "sold" it.