Thanks OP!! Just ordered for our trip in August.
I don't see anything anywhere on the site that states that you only have a certain number of days to use a "pre-arrival" CD so I can't see that being a problem. And, if I am reading it right, if you end up not wanting to order the CD after the trip (i.e., if you didn't get many photos taken or don't them or whatever and don't think it's worth it--) you can still request a full refund within 2 weeks of your trip completion. Here is what my confirmation e-mail said:
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Thank you for purchasing Disney's PhotoPass CD pre-arrival savings offer! Please keep this e-mail in a safe place as you will need it to order your PhotoCD after you return home from your Walt Disney World® Resort vacation.
What To Do Next:
Step 1: Visit the Parks and get lots of Disney's PhotoPass photos taken. Look for our photographers throughout the Parks and they'll be happy to make sure your CD is filled with as many photos as you'd like. The first photographer you see will give you a Disney's PhotoPass card you can use for your entire stay. View park maps and photographer locations!
Step 2: After your vacation, go to DisneyPhotoPass.com to view your photos. You will need to log into your account using your email address and password. Be sure to claim your photos within 30 days of your vacation!
Step 3: Claim any Disney's PhotoPass cards you used during your trip by entering the ID numbers after you log in.
Step 4: Place your order to recieve your PhotoCD.
Note: Additional shipping charges may apply if your order contains other products.
Satisfaction Guarantee/Return Policy: By taking advantage of Disney's PhotoCD Pre-Arrival Savings Offer, you are guaranteed to get a great value on our most popular memory keepsake. This e-mail contains your Promotion Code. You will use that code to get all Disney's PhotoPass images in your account on an archive quality CD as well as a copyright release that allows you to reprint and use your images in the sizes and formats that you wish. You must order this CD after your vacation. This promotion code cannot be combined with any other offers. If for any reason you are not satisfied with the photos and decide that you no longer want to order your Disney's PhotoCD, just let us know and you will receive a full refund. To receive a refund, you must request it within 2 weeks after the completion of your Disney vacation and you must not use the special promotion code to order Disney's PhotoCD. If the promotion code has been used, a refund will not be granted.