The short review:
Hooray! I'm 10 years old again!
I'm ten years old, and Star Trek is once again new and fresh and exciting. It's full of action and adventure. It's optimistic and bright without being smug and self-satisfied. It's dangerous and exciting without being a dark, dismal, Crapsack World.
When Mr. Abrams said, over the last year or two, that he "wasn't really a Star Trek fan", he was, evidently, lying through his teeth. And I applaud him for it.
The movie is wonderous. It hits every note perfectly. The funny parts don't slow down or cheapen the genuine urgency; the shout-outs and continuity nods are quick and casual.
I got choked up at the very beginning; Quel got choked up at the end.
The cast is splendid, simultaneously hearkening to the original portrayals of the characters, yet making the roles entirely their own. Zachary Quinto manages to do this with Leonard Nimoy standing right there.
For those poor, benighted souls who have not yet seen this spectacle on the big screen, I shall politely put the remainder of this behind a spoiler cut.
Everything is changed. Nothing is contradicted.
Mr. Abrams has accomplished what DC Comics has tried and failed to do as many as four times in the last quarter-century: the In-Continuity Reboot. He didn't just start a new version of the franchise cold; he used the old franchise as a starting point, and branched off into a scenario allowing a whole new direction.
Even more elegantly, that "old timeline" is still "there". That world didn't end -- and this is stated in the dialogue more than once.
So I can still run that Quicksilver campaign, if I can ever get it put together...
If you haven't seen it yet, go now. Boldly.