Alright, just got back from New York! It sounds like most people on here have already interviewed.. but here's my bit just in case it helps.
When I first arrived there were two student representatives to check you in and answer any questions (interview or otherwise) while you wait.
I never received an email with the names of my interviewers, just a general confirmation of time and place, but it ended up being with Trey Ellis and Carol Littleton (I believe it was her - looking at the faculty page). The interview started really casually. They asked where exactly I was from and it turns out they had both been to my little town in California! After talking about that for a while we jumped into the interview more fully with Professor Ellis asking the majority of questions. I'm having such a hard time remembering what exactly they asked, but it was basically to learn what I've been watching, what inspires me, what I do for a living, what kind of stories I want to tell, why Columbia/the east coast, and because they know I'm interested in television they spent some time getting to know what I like to watch and just my interest in that in general.
Then it was time for my questions. To be honest that part felt like it went on forever, haha. The interview lasted 30 minutes and I feel like the question portion was, at the very least, 15 minutes of it. I would ask a question, they would answer, and then they would look expectantly at me for the next one.
All in all the interview definitely had that conversational tone/aspect to it like everyone else experienced with their interviewers, but one difference was that they didn't ask about any of my submitted materials at all aside from some points from my personal statement.
Overall, I think it went well. It's a very competitive program and I didn't leave there thinking "I'm in," but I felt like I gave it my best and hopefully they saw that.