I was interviewed by the Graduate Students Services Coordinator on the 18th.
She started off by asking me to introduce myself and talk about my resume. Then, it was quite similar to Kurt's. She asked me to explain my trajectory towards MSOR, why Columbia, what kind of jobs am I looking for once I'm done, would I like to work in the U.S. (I'm an international applicant) and then she asked me to summarise my current job scope apart from the description listed in my resume.
She mentioned the same thing as to when the results would be out, before Christmas the latest. I also asked her would it be possible to complete MSOR in a year for a Spring applicant, she said yes if I want to load up my credits, but most students choose to do an internship in between. Lastly, I asked about the number of Spring applicants for 2015 and she said she couldn't give an exact number, but it normally averages to around 15-20% across the IEOR grad programs.
I hope that helps.