I had an interview at USC in October and was accepted on Dec. 2. The format of the day is really easy. We got there, recieved a packet with general materials (i.e. about the school, their program, status of my application...etc). They told us about the school and about PBL. We filled out some forms and then we did a brief essay on some topic, I don't remember exactly what it was but it was really easy to write. We then went on a tour of the dental school and sat in on a PBL class. Ideally the class is going over one of their case problems, but in our case they had already finished for the morning, and just talked to us about the school, the PBL program, etc. We then had a meeting with the financial aid guy. Then lunch with some current students (there were probably 2 or 3 students for 40 interviewers).
After lunch we had a mock PBL session with about 10 other students. There were 2 admissions people in the room and they observed how we worked in the group. The case we used is the same case they have used for several years. It doesn't really matter what the case is though because they are just seeing how you react to the situation. Honestly it was kind of frustrating because people were not really being themselves and were obviously trying to make themselves stand out-which made them look pretty stupid-if you ask me.
As far as chances after the interview-I don't really know. Somebody posted recently that they had been told that around half of the class was full. That leaves another 70 or so spots available. Everything I heard indicates that if you get an interview chances are you will also probably get accepted.
Let me know if you have any other questions.
