So I had my interview today:
We met at a coffeeshop, and it was super casual. The interviewer told me not to be nervous - that Columbia basically has made its decision when they ask to interview you, and that this is just more reinforcement than anything else.
It was fantastic - definitely more like a conversation than a Q&A. Although -he only asked me two questions that I'd already prepped for - Why Columbia and what other schools are you applying to? Even with the latter question - I just vaguely said that Columbia was my number 1 choice but that I was considering other programs, and he didn't press me further to find out which ones. He didn't ask me the ethical dilemma question - and actually he didn't flat out ask me "why an MBA?" No questions about leadership. I rolled my reasons into other questions he had asked....but we talked for about an hour, and he only really asked me maybe 6 questions - all of which were very specific to my industry, actually. My favorite question he asked that I hadn't prepared for was, "So assume you have your MBA and you are placed back at your company. What are the three major changes you would immediately work on implementing?"
All in all - FANTASTIC interview, at the end he told me he was going to recommend me without any reservations.
So....now we wait!