This movie was absolutely awesome! I can't seem to describe it without devolving into a 14-year-old again, unfortunately.
Yes, there are differences, but it's not intended to be a remake, but a reimagining of the series, and in that regard, it's amazing. Chris Pine as Kirk and Zachary Quinto as Spock were perfectly cast, inhabiting their characters without parodying them (Pine especially, when it would be so easy to devolve into a bad Shatner impression). The remainder of the primary cast is just as amazing.
If you aren't a Trekkie, you should enjoy it, but if you are, there are so many little in-jokes that it adds to the experience (catch whose beagle Scotty uses, for one).