In truth, the mixing of cooking methods and of ingredients has been around as long as PEOPLE have moved around the world. By this I mean that emigrants (willing or not) bring with them the idea of the food they know. Once they can, they try to make what they remember with the ingredients they have available where they are, using the cooking techniques they have access to. Look at the cooking of the American South, so strongly influenced by slaves who were brought from Africa, as only one example.
What is a fairly recent phenomenon is the need to name such age-old trends. "Fusion" has been around in the US for at least 10 years. As for Australia: I've got a book called Fusions by Martin Webb and Richard Whittington, first published in 1997. Which means that it was probably there a couple of years earlier. Nowadays, though, I think we should just say "IF IT TASTES GOOD, IT IS GOOD !
I am blessed to live in New York City, where I can eat in restaurants that make all kinds of combinations -- some of which work, many don't. I can buy all sorts of ethnic ingredients, which I love to mix into my basic-American cooking to make dishes that are mine. In fact, until I find out the (if any) terrible social and ecological costs, I am more than happy to mix everything.
When I read my copy of Vogue Travel & Entertaining from Australia, I drool. It all looks great to me. The more global we get with food, the more we can support LOCAL AGRICULTURE, and the better the world might be (the idealists view).
Let's eat!!!!!!!!