A quick advisory from the Walt Disney Parks & Resorts:
Walt Disney Parks and Resorts Merchandise Update
Effective September 19, 2011, Walt Disney Parks and Resorts Merchandise locations will no longer ship Guest packages to the country of Mexico. The government of Mexico levees taxes of over 500 percent on the value on products made in China; this cost must be paid by the receiver (i.e., Guests) before packages are released by Customs in Mexico. For this reason, many shipments are abandoned. Although our products are made in many different countries, our goal is to avoid confusion to both Guests and Cast Members on shipping options.
Can you imagine having to pay a 500% tax on a gift you purchased in a park? Most of the things we use every single day are made in China (we are all aware of that), so it is easily understandable that Disney doesn't want guests to have to deal with these kind of things (I would be angry too, if I knew I had to pay such a high fee). On the other hand,we're quite sad for visitors that come from Mexico, as they will not be able to have anything Disney-related shipped to their homes.