In September, the Australian Classification Board refused to let Left 4 Dead 2 pass, stamping it with the "refused classification" label.  Publisher EA had planned to make an appeal, but the classification page was recently updated to display an "MA15+" classification -- Australia's idea of a "mature" rating.

This might be a direct result of Gabe Newell's doing.  The head of Valve traveled down under to visit a L4D fan recently, and he has apparently been using this opportunity to work with the Australian Classification Board.  There aren't many details yet, except that a decision over Newell's appeal would be made some time around October 22; an edited version of the game was also submitted in case the appeal is overturned.

The new MA15+ rating was most likely issued for the edited version then.  However, Australia has changed its mind before, as we saw with Warner Bros.' and F.E.A.R. 2, which was originally refused classification but later received the MA15+ rating.