Ostensibly, this is a new trailer for Kingdom Hearts 2.5 Remix, which comes out this December for PS3. It looks great and all, but really what's exciting here is the little teaser for the game we've all been waiting for: Kingdom Hearts III.
The teaser starts at 2:30 or so. Here's hoping we're getting a real trailer at E3 next week too. Still no word on any sort of release date (or release year) for the third Kingdom Hearts game.