When you arrive at the hotel you can Pre-register (anytime after 7am). They will go through the entire check in process, issue you Key to the world cards and everything. Then, if the room is not ready, they can store your luggage and they will issue you the card to call back. It is very convient that way. You can call from any house phone (or cell phone) and find out your room number so when you return you can go right to the room, thus not having to wait in line at the front desk again. Depending on when you are arriving you have the potential to get a room early. It all depends on if they were sold out the night before. If they have rooms that were not used the night prior in the category that you are booked in you could get lucky and get a rooom when you arrive. Otherwise no harm done, you are pre-registered and can enjoy the parks until the room is ready. Also (especially in the Villas since there are not that many rooms) the earlier you check in (pre-register) the better chance you have of getting a room that is "more desirable". They do not pre-assign rooms (unless you have medical needs or are traveling with another party, so they are first come first serve, the earlier you check in (room ready or not) the better chance you have of getting some options in where you want the room to be, smoking or non,etc...