I've been on 3 interviews so far and they've all been about the same. Basically, they have you interview with 5 to 8 people usually 1/2 hr at each interview. In my experience the interviewer usually spends the first 20-25 minutes talking about their program and their roles in it, and then the last part of the interview is for your questions. No one has really asked me any tough questions, or even any questions that specific to my application. No talk about your most interesting case or what are strengths/weaknesses. Mostly I've been asked where do I see myself in 10 years;academic vs private; which field of path do you like the most, stuff like that... Really benign so far, very laid back. Anyways, good luck and I hope all goes well.