As the article linked to below mentions, there has been no announcement about the creation of an Australian Kindle store. I stumbled across this myself just recently. If you sign up to the Australian site it seems to interfere with the free and discounted offers available via the US Kindle store. So something to keep in mind.

For more visit:
http://www.the-digital-reader.com/2013/11/12/amazon-launches-local-kindle-store-australia/