I just had mine about a month ago and am waiting to hear back...but what I can tell you is the that the interview is pretty nice.
I've had two now (one back in October '06...unfortunately I didn't get in that round) and in both interviews they asked the following questions, pretty much in this order too (if I remember correctly)
1 - What part of your education made you want to become a doctor?
2 - Why do you want to study at the university of Queensland?
3 - What do you like to do in your spare time and elaborate on 'blank' extracurricular activity?
4 - What do you feel will be the major health issues that you will face when you are practising?
5 - will you be ok being away from home for this long, and do you have any kind of support network while in Aus? (eg, family, friends etc.)
That's all I remember, and I know at the end they get you to ask you some questions too (if you're interested) As an international applicant, the doctor interviewing me had great interest in the fact that I had travelled around through Asia for the last 6 months...so if you've done anything like that or travelled to a different part of the world, mention it as they were REALLY stressing the international component.
Hope this helps, and good luck!