Apple notes that "due to unexpected challenges" the film festival will be postponed until after the holidays. Many TUAW readers let us know they were unable to register, so server errors could be to blame for this postponement.
If you have already registered, Apple will contact you shortly with the new, rescheduled date. If you haven't registered for the film festival, and would still like to, you can do so on the Apple website.
Thanks to Michael, David, and others for their tips!