Australia won't be playing Left 4 Dead 2
The problem lies in the rating system. Australia doesn’t have a “mature audience only” classification, so if a game is considered too violent or graphic for the average 15 year old, it’s banned. Seems like something that’d be easy to fix, but apparently their attorney general doesn’t see the need for people to prepare for the coming zombie apocalypse.
Don’t worry Australia. You can still play Peggle.