The interview day this year consists essentially of 4 parts:
1. Your interview - very low key, you have 1 interviewer, lasts about 30 minutes, will take place in the morning before lunch/tour or in the afternoon after lunch/tour.
2. Brief meeting with Dean Nicholas - I think this starts around 11:30. He is the Dean of Admissions and will briefly talk to you about some of the highlights of the school/program/curriculum/city/etc.
3. Lunch - This is one of the best parts because you have at least 2 students that will eat lunch with you and the normally 6-10 other interviewees and try to answer any questions you have about the school, give you lots of information, tell you all about our super cool activities with the P&S Club, etc.
4. Tour - Two students will take the group on a 1-hour tour of the medical campus to include the Children's Hospital, lecture hall, library, and a few other places.
I'm a first year and occasionally do the lunches/tours, so please feel free to ask any other questions that you might have.