Halloween was not a part of Australian culture until relatively recently.
It seems to be increasingly "celebrated", although I doubt that many people who walk their children around knocking on doors would have any idea of the origins or significance of this "festival".
My opinion, admittedly potentially seen as excessively cynical, is that the increasing awareness of Halloween in this country may have originated with the increasing proportion of television air-time dedicated to programmes produced in North America rather than locally-produced programmes, but that it is now driven by commercial interests wanting to increase sales on the back of anything that will drag money out of parents' pockets/wallets.
I also see that here in Australia the increasing "celebration" of Halloween in child-care centres and primary schools coincides almost exactly with the decreasing celebration of Christmas and Easter. Political-correctness gone mad has made it unacceptable to celebrate Christmas in child-care centres and primary schools in this country but it seems that "celebrating" pagan festivals is acceptable!
All that being said...and my rant being completed...
Happy Halloween and a blessed All Saints Day.