Oh, just give me this movie now. Give me, give me, give me. NOW!
I don’t think there is much to be said about this trailer outside of “it’s cool!”. But I will mention this: the biggest quality the trailer has is that it makes the third movie seem bigger and more important than the last two. This is essential to keep everybody interested and coming back.
Also, Disney very wisely offered themselves the code to embed this trailer in any blog or site. I always wondered why movie studios didn’t always do that. After all, it’s in their best interest to get the trailers as widely seen as possible.