Scott said it best...if you dont get accepted to SIU...you are pretty much waitlisted until they know that you are far enough away from being accepted that it is safe enough to send a rejection letter. If you are within the range to get accepted (i.e. 1-10 on list) you will be considered (I am assuming here) probably until the first day of school. Point is, they dont flat out reject you (from personal experience) until they are 100% sure you have no chance to come off the waitlist.