More information about the trailer, according to fictograph:
And I am just like "Wow, this pales in comparison to the real sequence." DW used some new tech with better lighting and rendering quality, and the difference is way noticeable on a color-corrected HD screen. So yeah, when you watch the real movie next year, it’ll be even better.UPDATE: Added new 1080p video and screenshots (below).
UPDATE 2: Added official trailer.
UPDATE 3: According to a comment below by Smirktastic, the teaser music is "not John Powell's music, it's just something used for the teaser trailer, however John Powell is scoring the film and will no doubt have his own music in place of it in the final cut."
UPDATE 4: Thanks to Stormbringer88, we've identified the music! It's "Beyond the Clouds" by Kevin Rix. I posted a YouTube video of the music below. The music in the trailer starts a few seconds after the one minute mark.
UPDATE 5: According to kris0ten, the teaser was leaked. It was supposed to come out on Tuesday, July 16th, two days before the DreamWorks Comic-Con panel. No one knows who leaked it, but it was spotted here first.