Unfortunately, it doesn't really clarify whether or not you have to pay a new application fee if you opt to send new materials.For everyone applying for the first time, if you unfortunately don't make it into USC this round, USC will automatically want you to re-apply for the next semester (Spring '12) and will waive you application fee. You'll probably be getting an email about this 1-2 months before the Spring '12 deadline. You will be given a choice of either re-submitting the same materials or requesting to add new materials to re-submit.
Something else to think about for Spring: the numbers are all over the map, but traditionally there are 600-900 applicants for Fall and only 200-300 applicants for Spring, but 60 slots for both. I'd wager that about 15 of those Spring slots are taken by Fall waitlisters (as happened in the year I waitlisted for Spring), meaning 45 open spots for Spring. So chances of Fall acceptance: 8-12%. Chances of Spring acceptance: 15-22%.