According to a forum post
early in the new year by Valve Software's Chet Faliszek, the developer is still mindful of the censorship of the Australian version of their zombie shooter Left 4 Dead 2, revealing that they are "exploring the options" since our country's introduction of an R18+ classification, but stopping short of confirming a submission for re-classifaction (thanks GamespotAU
No need to flood us with emails. We have been exploring the options here and what we can legally do. We will have more information on this when we understand the issues fully and how we are moving forward but don't worry any cost associated with it doesn't worry us, this is something we want to do.
When Left 4 Dead 2 was originally submitted for classification to the then Office of Film and Literature Classification ahead of its 2009 launch, the title was deemed in excess of the maximum MA15+ rating of the time and refused classification. A modified version was then created for the Australian market, removing most of the blood effects and making zombie corpses vanish more rapidly.
Australian's classification legislation permits a game to be submitted for an updated rating after two years, which wouldn't be an issue for Left 4 Dead 2. However, the game was originally published, and submitted for classification by Electronic Arts under their EA Partners label, so it's possible the legalities of that arrangement might complicate things in this instance.
Warner Bros. recently confirmed
they are submitting Mortal Kombat: Komplete Edition hoping for an R18+ classification after the game's original version was refused classification under the old guidelines --seemingly avoiding the two year requirement by the bundled DLC making it effectively a distinct product-- and Team Ninja's Ninja Gaiden: Razor's Edge for Wii U recently became
the first videogame to receive the R18+ stamp in Australia.