If you have an invite you're able to play in Australia. I don't own an Android but a couple of my friends are playing already. There was an article in the Sydney Morning Herald about the game too but I can't seem to locate the link at the moment.

I am in New Zealand, and ingress is not available in store. Had to Google for the apk, and allow unknown sources. I had an invite from entering my email to ingress.com.

Runs fine (battery hog) but unfortunately there are hardly any portals in Christchurch, and the ones in the centre of the city are inside the red zone cordon and can't be got to o_O

I just took a look using the intel map. There seems to be plenty of portals and activity in Australia, at least where I looked (in Sydney and Melbourne).