... It's because J.J. Abrams is involved in it. Even though some of the trailer looks, well, non-Star-Trekkish in certain ways, I'm going to give him the benefit of the doubt because he has shown multiple times that he knows what to do with a story (the evidence: Lost, Cloverfield, Mission: Impossible III, although I haven't been able to stand more than a few minutes of Fringe ... ).
Wired magazine allowed Abrams to take over their issue and here's an interview from that issue (PG-13 for language):
This is a storyteller who seems to know what stories are for. Granted, he may mess it up entirely, but I'll wait and see.
PS: Beyond the trailers, there's a film clip from Star Trek on iTunes now that shows promise, if only because there seems to be a cool technological trick to teleporting in warp space ... I'm intrigued, and I like Simon Pegg as the new Scotty too. Not sure about the new Kirk but he's supposed to be a jerk, right?