I'll be attending the Nov 14' intake. I'll be finishing up work in the mid-summer and then I plan to travel around SE and East Asia for a while before heading to Spain. I'm not sure on the schedule yet, but I guess I'll arrive there in early November since I won't need the intensive Spanish. I'm incredibly excited to spend a year at this top notch program. Entrepreneurship is something I'm interested in in the long run, and from all appearances it doesn't look like it gets much better than at IE.
As far as the interview goes there is no magic bullet we can give you. With that said, you should try to emphasize a few things. IE is big on fit. Diversity (background, experiences, etc.) is important to them. Their MBA has a lot of team collaboration, so they look for applicants who know how to work well with others, lead others, etc. You should be prepared to give clear reasons why you want an MBA, why from IE specifically, why now, and how you can benefit from, and bring benefits to IE and your teammates in your student groups. They will probably ask you some business questions related to your background, or where you want to go.
It's important that you have clear answers to these questions. However, don't lie or try to create a story that you think they will be impressed by. Stick to your motivations and show how IE can help you get there. And again, it's always good if you can demonstrate not just how IE can help you, but how you can benefit the program, too. If you're able to present these things clearly throughout your entire application you'll do well. It's a good sign that they're interviewing you. That means they're at least intrigued to learn more about you.
Best of luck to you.