Basically, for $39.99 you'll get the free Limited Edition upgrade if you buy early, which includes an exclusive Disney collectible pin.
Square Enix also sent over the updated packshot and some Kingdom Hearts Re:coded shots too.
Take a look.
For the devoted followers of the KINGDOM HEARTS series, SQUARE ENIX, Inc. today announced the Limited Edition for KINGDOM HEARTS HD 2.5 ReMIX. Fans that pre-order the Standard Edition of the game at participating retailers will also receive a free upgrade to the Limited Edition (while supplies last), which includes the exclusive Disney collectible pin featuring Sora and Mickey Mouse.
KINGDOM HEARTS HD 2.5 ReMIX will be available for North America on December 2nd, 2014 for the PlayStation®3 computer entertainment system, and will be priced at $39.99.