FINALLY. After a few delays, protracted negotiations, then more delays, Apple has today finally rolled out iOS 6 turn-by-turn navigation to Aussies.
Siri will now tell you where to go if you hit the Directions button with your mode of transport selected as "Car".
Apple had originally promised to bring turn-by-turn navigation to Aussies before the end of October after failing to ship it at launch. The service was delayed again two weeks ago, presumably due to negotiations still underway with Australian mapping providers.
It's still based on Apple's frankly awful Maps though, so be prepared to be told to go up more than a few one-way streets.
Thanks to everyone who sent this in.