Hi all, I got accepted into the IESE Young Talent Program back in 2010 and have been pre-admitted to the MBA with start date in the fall of 2012.
Pixaar, if possible/reasonable (e.g. considering cost to travel), I would always aim for a personal encounter. Skype is nice and I am sure one can bring his arguments/motivation across, but the personal encounter always adds an additional layer to the whole process. Plus, in case your assessment day is on campus (?), you could combine your stay with a class visit or connecting to current students, which is great! When I had my interview, IESE arranged for lunch with 3 current students from my country, which was great to ask different types of questions. Unfortunately, I could not participate in a class since I had my interview just after lecture period had ended.
Good luck everyone for the interview/assessment day!

Cheers