coolio,
i interviewed there last year. first, i'd say don't worry. i remember that everyone said their interviews went very smoothly and that they felt that they were positive experiences. i had a great interview with a family practice physician. we talked about all sorts of off the wall topics, but we also definitely spoke about all aspects of my application. i think there were about 15 interviewees, it was pretty crowded. be prepared to answer any questions surrounding your personal statement, as well as the rest of your application. i didn't get any ethical questions, but i was asked why i thought the media treated the death of princess di differently than the death of mother theresa...that lead into all sorts of conspiracy theories..it was fun. if you are asked any ethical scenarios that involve patients, a good rule of thumb is to always put patient automony and patient well-being first..then go into your own beliefs if you feel like the interview is going along smoothly.
good luck. they are rolling admissions, so an interview this early in the game is a very good sign.