It's been years since Valve announced its intention to add Australian currency to Steam, but good things (or let's face it: moderately convenient things) come to those who wait. According to messages sent to Steam developers and reposted on the Steam forums (thanks PCGamesN), Australian currency will be displayed from November 21 onwards.
Although that isn't for a week, there's already an announcement post on Steam outlining what the changes mean for Australians. Basically, all it means is that you won't have to conduct a currency conversion every time you want a price for a game, but of particular note is that Steam Wallet currencies will convert to AU dollars "at a conversion rate dictated by market value at the time of conversion".
Also of note is what will happen to Steam games in cases where the developer hasn't nominated a new Australian price for their games. It appears that if a game doesn't have an AU price in the database, it simply won't be visible to Australians. "Most games previously available in USD are now priced in AUD and are available for purchase in Australia, but an occasional product may be missing until it is priced in AUD."
While it's unlikely the big name publishers and developers will refrain from adding an Australian price, who can guarantee that the folk behind Leisure Town, for example, will think to update their details? Let's hope for posterity that they do. In any case, I'll be keeping a close eye on proceedings come November 21.