LIU is a group interview. I interviewed there at the beginning of December and will most likely be attending. It is really informal. I interviewed with 3 other applicants and 2 faculty members. We went into one of the professors offices and sat around a desk. It was more of a conversation and they asked each us a few questions, went over the program, and allowed us to ask questions. I honestly can't remember all the questions they asked, but they did ask if you were President what would you change about our healthcare system? They also asked what friends would say about you (3 strengths, 1 weakness), why LIU, why NYC? Just be yourself and you'll be fine.
They have 2 students there with you while you wait in a classroom with a bunch of other applicants. After the interview, one of the students will take you on a tour, and then you're free to go. It was completely painless. The students all seem really happy and I couldn't have been more impressed. They'll let you know if you got in within a month.
Good luck!