Despite all of the differences in cuisine and so on, (the food is VERY different) the Australian culture is very different to that of the U.S. Australians as a whole practice a very Egalitarian mindset whereas Americans are obsessed with status so, essentially, they're opposites. Where in America you respect strangers by calling them "Sir" and "Ma'am," here absolutely everyone is "mate" regardless of relation. This was VERY off-putting for me at first. If you know anything about Tall Poppy sydnrome, it's like a plague here; anyone who starts to show a bit of ambition or is more successful than their peers is immediately cut down. Australia LOVES an underdog, but will abandon them at the moment of success. It's so different.
There's also an Australian form of humor called "takin' the piss" which is when one person becomes a point of mocking, teasing, and scoffing which most American's would find VERY rude if they didn't understand how this humor works. You're not meant to get all bent out of shape about it, but to fire back with more mocking, teasing and scoffing or to simply mock yourself. A lot of people I first meet will "take the piss" out of me when it comes to the USA. It's hard not to be defensive, but you just have to roll with it. They're not being rude or having any hard feelings by Australian standards so...when in Rome...
I live in rural Australia which is NOTHING like the DFW metro where I'm from. Nothing is open on Sundays. Everything but the grocery store is only open from 9-4/5pm and, if something is open on Saturday, it's only until noon. It's insane. I don't know how much better the capital cities are about this kind of thing but I miss my 24 hr WalMart for sure. If you sleep past 7am here it's considered "sleeping in" even on the weekends....it's a whole new world. I hate it here so far but, if you have the luxury of living in one of the capitals, your life will be a bit more charmed than mine I'm sure.
Just thought I should add that the cost of living is painfully high. Things cost twice the price point on avg. compared to what you would pay in America and sometimes is as much as 4 times more expensive. A can of coke at the local pub costs $2.50. There's no such thing as "free refills" unless you're at an American restaurant (i.e. Subway or BurgerKing) A house that would cost $90k in Texas sells for $650k here. I could go on and on...it's hard to get a job if you don't have some kind of certificate, diploma,or degree even as a receptionist no matter how much experience you have. I could go on and on...
The economy is going strong. I'd say Australia is one of the safest places to be in the world at the moment as far as job security goes. The public healthcare scheme is pretty frickin awesome as well.