With the new GST laws being effective 1 July this year, Amazon is now going to redirect all Australian customers to the Amazon Au website (and probably prevent you from checking out if you tried to buy on the US website with an Australian address).
As a compromise, it will expand the range on the Au website to include some US items. Unfortunately, we won't get the same range and prices will probably be worse than if you bought directly from the US site in the past.
Sigh.
Source
"sometimes the things you see might not be real and the things that are real you might not see"