Previously, the site gave users the ability to stream trailers in 480p or 720p, along with providing download options for 480p, 720p, and 1080p. Trailers uploaded to the site after an approximate date of May 22 no longer have any download options and can only be streamed in-browser at 480p or 720p.
While trailers uploaded before May 22 can still be downloaded, Apple appears to be removing the option from movies with multiple trailers that have a trailer uploaded after that date. For example, Disney Pixar’s Monsters University has trailers that were uploaded on the following dates: 6/20/12, 3/08/13, 5/20/13, and 5/22/13. None of these trailers have download options.
Disney’s Planes, on the other hand, has trailers that were uploaded on the following dates: 3/15/13, 04/04/13, and 5/17/13. Each of these trailers can still be downloaded at all resolutions, including 1080p.
So, while older trailers can still be downloaded from the site, Apple appears to be removing downloads from older trailers as newer trailers are added, slowly phasing out the availability of trailer downloads altogether.
It is not clear at this point why Apple has begun phasing out movie trailer downloads, but we have contacted the company for more information.
(Thanks Eduardo and Theo!)