AntGod,
My interview was very casual, beginning with all the interviewees and a few current students sitting around in the lounge area of the health sciences building. It dragged on for a bit, and then they started calling people in for the actual interview. You'll be assigned two or three interviewers and a time slot. I got the anatomy professor and the dean. They were very nice people, and the dean even checked my shoes at the end to make sure they would be suitable for taking a tour outside in the snow (and no, I did not ask her to do that!!). The questions were typical, check out the interview feedback page here. Personally, I felt the whole ordeal was a little unorganized, and more than half the people left before lunch was served. They said we could leave right after our interview because it was snowing and they didn't want to keep us in case it got worse. No tricks to look out for, just try to have fun, meet some people, and enjoy the views of Maine.
Best of luck on your interview!