One thing I learned about USC and the whole application process is that they are SLOW. Last year, when I already had 3 interviews set up, I got a letter from USC sometime in Sept, thinking it was the interview invite, but it was just a letter saying that they received my app, but they will not begin to review any apps until they get their new class situated (yeah USC 2006!) So be patient, in the application process, USC did everything the slowest.