It seems that the “Office of Film and Literature Classification” in Australia, similar to the ESRB, has refused to classify the title. As a result, it is illegal for the title to be sold in that region. The reason for the refusal? No one has confirmed the reasoning yet – but if you have ever been a fan of the Fallout series, you know that the game is rife with vices and potential violence that could even put GTA IV to shame. Fallout 2, for instance, ended up being released with a special European version that lacked children, due to concerns over violence.
I hope Bethesda can work things out and get the title released in Australia, but I also hope they do not let arbitrary rating boards compromise the integrity of their game. It has a lot to live up to, and it will be much harder to live up to if they cave into demands to censor or restrict gameplay. That said, bans have been almost universally ineffectual in the past, and if people want to play, they will play, regardless of where they live.