Turn-by-turn voice navigation is a feature in iOS 6 that was not available in all countries at launch. While Apple’s own website still says the feature will arrive in Australia this month, it has already been turned on according to recent reports. The feature should have been available in October but according to ex-Apple-manager Scott Forstall, it just wasn’t ready in time.
If you live in Australia an you are running iOS 6 on your iPhone 5, 4S, and 4, you can now enjoy this feature. Apple is continuously working on improving the map experience in iOS after a rather bumpy start (where the CEO himself had to apologize and where eventually Scott Forstall had to leave the company) so this might be just a small step in the right direction (which we do agree should have been there at launch)