With Hurricane Charley, Disney waived the 5-day rule, and let people modify their plans (for a certain window-- like through the 18th or something)
That said, I wouldn't worry about a hurricane. It is extremely rare for a hurricane to hit Orlando head on like Charley did, since it is an inland city-- usually the major concern is for cities within a few miles of the coastline because of the storm surges. The most you will get if there is a hurricane is the remnants, so, a lot of rain. I'm sure there will be no allowance for cancellations because of rain.
Even with Charley, Disney bounced back extremely quickly-- the next day, the only reminders of the hurricane were some uprooted trees! And Charley was a very strong storm!