I think Australia is showing up first because your sort is set to "Country: A to Z" and those items simply share a release with a bunch of "U.S" items that you own, not so much a function of an Australian prior release date. If they were released in Australia at all, they would show up first.
As far as "U.S." toys goes, that's the way we used to do things a few years ago - we had a bunch of countries over on the left and everything branched out from there, e.g. United States > Cybertron > Scout.
It was determined that this method was limited, so we switched priority to toylines first, with the actual countries of release/packaging type dictating where they were found and how they were presented. So now instead of the path you see above, we have Cybertron > Scout and then consider the countries of release.
So it's not so much a "U.S" toy vs. an Australian toy, it's a shared-packaging type thing. With a majority of this (more recent) stuff, Hong Kong, Taiwan (basically all of Asia except for Japan), and Australia get the same packaging as the United States, Canada gets packaging that is also used in Latin America, and Europe has its 12-language packaging.
And now, with Hasbro doing their whole global initiative thing, I don't think they think of toys as "U.S." or "Canadian" anymore. Even back then, look at Armada..., yes, the United States was deemed to be the primary market, but the "U.S." packaging was meant for all of North America. Also, if you've seen photos of the upcoming RID (2015) toys, they're all in multilingual packaging. The U.S. is considered just another market these days. Heck, in the States we don't even get the tail-end releases of lines anymore, with them being released elsewhere on the planet in large numbers.
With the way this is set up, I have a feeling that you'll find that you own a lot of "Canadian" items as well.
To tell the truth, I was just thinking about this same type of thing last night and was wondering, and I don't know if it is even doable on a user profile, if it would be possible to show ONLY Australian toys - those toys ONLY released IN the AUSTRALIAN market and NOT toys that are cross-labeled with the United States or other countries. So, for example, the Red Rooster toys would show up, but Dark of the Moon toys also released in other countries would not. Perhaps this could apply to all countries, as well.
Like I said, I don't know if displaying something like a specific country-release is possible on the profile...something to think about, though.
MIKE
engledogg