From the Disney Reservation site for 2013 policy:
Cancellation Fees Prior to Guest Arrival
Cancellation of Reservation - If the reservation is cancelled amounts paid, minus cancellation fees, vacation insurance plan cost, and other amounts owed, will be refunded. For cancellations made 44 days or less prior to guest arrival, there is a cancellation fee of $200 per package, plus any cancellation fees assessed by third party hotels or other suppliers. No refunds are given for cancellation of a Grand Gathering experience made 6 days or less prior to the experience date.
Guest will be responsible for any cancellation fees assessed by an airline. In the case of a non-refundable airline ticket, the cancellation fee is equal to the entire ticket price. Cancellation of a refundable airline ticket must be made at least 24 hours prior to the scheduled airline departure time.
Vacation insurance plan cost is nonrefundable.
Change Fees and Changes to Reservations Made Prior to Guest Arrival
Changes to Reservation - For a change made 44 days or less prior to guest arrival that results in a change in the package price, a change fee of $50 per package, plus any change fees assessed by hotels or other suppliers, will be charged. Such change fees must be paid in addition to any increase in the package price resulting from the change. If air travel has been ticketed, guest will be responsible for any increase in airfare as well as the change fee assessed by the airline.
Changes to reservations which affect outbound flights or first night's accommodations must be made at least 7 business days prior to guest arrival. Land portions of the reservation cannot be canceled without also canceling the air portion of the reservation booked through Disney. Airlines/hotels/suppliers do not permit changes in certain situations. All existing travel documents must be returned to Disney via overnight delivery service and revised travel documents will be delivered to guest via express service, both at guest's expense.
Disney reserves the right to restrict changes to any reservation.
Refunds
No refunds will be given to no-shows. No refunds will be made for unused admission tickets, options or features, including meals. No refunds for airline tickets will be made after travel has commenced or if a flight is missed/delayed. Any refunds allowed by Disney in its sole discretion after arrival must be requested in writing within 60 days after departure and will be assessed a $25 processing fee. All travel documents (including paper airline tickets) must be returned to Disney in order to process any refund. Disney reserves the right to make refunds in accordance with the method that payment was received. All appropriate refunds will be made through the guest's
travel agent if the reservation is made through a travel agent. Disney is not responsible for the receipt of refund monies by guests from their travel agents.