It all depends on your mindset going in. It's only going to be that way if you take the initiative. Besides that, I don't think you're well-informed if you think the Greek fraternity experience is the best you can get out of university. You are, first and foremost, a student. Contribute to your campus, join student clubs, meet a sh*tload of different types of people, and you'll be a better person for it. And of course, you'll still have time to drink your ass off. 🙂 Universally, almost everyone loves to party. So don't restrict yourself to one group of people. Frats and sororities are not the be-all and end-all.
And as for Australian universities, how would they be any different? They've got all the same mixes of people. Consider yourself lucky, because I've always wanted to visit. The nightlife in Melbourne/Sydney seems fantastic.