Interviews are very important. I had my interview @ Midwestern CPG with 12 other people. We were all seated in a room, and the Dean of Admissions came in and told us that the time to worry about our pre-pharm stats was over. He said, "Your numbers & stats have gotten you to this point. Now it's time for our interview committee to get to know you and make sure you are a good fit for our school."
They will ask questions like
Why pharmacy instead of another medical profession?
Why have you chosen our school?
Where do you think the pharmacy profession is headed in the next ten years?
Just be yourself and be honest. It's not a stressful thing, but as a pharmacist you need to be intelligent, well-spoken, and articulate; not just a science nerd.
Good luck!