The bottom of most of the iPad mini pages on Apple's Australian site no longer says 'WiFi+Cellular models arrive in late in November', so I think we'll see it in stores today. So, fellow Aussies, post your luck in finding them in stores.
Just an update. I've got an email from Telstra saying the iPad mini is now available, so today is definitely the day. I'll be going into town soon to have a look.