The lack of an R18+ classification for games in Australia has long been a stupid/technophobic/embarrassing/ill-thought-out situation (delete as you see fit). While there's no sign of an imminent change to the law, a discussion paper from the Attorney-General released yesterday does open the door to that possibility.
The question of why games rating schemes are entirely different to all other media is a constant topic of discussion on our sibling site Kotaku. The discussion paper puts both sides of the argument, as well as explaining how to make submissions (which, you'll be pleased to hear, can be done electronically).
As ever with governmental matters, a cool head makes sense no matter what view you hold -- ranting and raving rarely makes much impression. Hit the link for the paper and details of how to make your submission, which must be in by the end of February.
An R18+ Classification for Computer Games – Public Consultation [Attorney-General's Department via Kotaku]