@ MrMidas21: I'm living in Victoria and the server I'm on is located on the US west coast. I get ping ranging all the way from 190ms to 280ms if it gets bad. Not idea conditions, I realised that much, but it's not bad... Completely playable unless you're extremely impatient or really want to play PvP.
If it's PvP you're into, which I know a lot of people are, like DP said, no way the servers will be based on Australian soil, so you're most likely going to have to use some kind of tunnelling service to get better ping if you're really into that kind of thing.