Before I continue with what I liked and didn't like, I have to state I don't think Classic Trek complainers have a leg to stand on. The movie makes clear from the first scene (part of which I missed because I was late to the theater) that this is an alternate timeline--I mean, if I picked up on this standing in the aisle, waiting for my eyes to adjust whilst holding popcorn, I should think most audience members would be able to as well.
Now for what I liked (and the reason I will rent the movie multiple times when it comes out on DVD): the interactions of our favorite Classic Trek characters. Reality-wise, it is unlikely that all these people would be assigned to the same ship first go out of Star Fleet Academy. However, it's a good excuse to watch the characters together. I spent most of the movie chuckling to myself--not just over things like, "I'm a doctor, not a physicist" but over little things like Kirk leering at women even while half-drugged and Scotty going on and on and on about food.
And the casting is excellent! Visually, I think Chris Pine is the closest to his original (Kirk). I know, I know, everyone thinks Zachary Quinto (Spock) is the closest and behavior-wise, he is, but Chris Pine has the young William Shatner look. There are a couple of instances when he looks exactly like the young Shatner--when waiting to be transported off the ice planet and when on the bad guy's ship: it's a little uncanny.
Zachary Quinto is excellent, of course. The thing I appreciated the most about Quinto and the others is how faithful the actors are to the body language of their originals. I really felt like they--or JJ Abrams, the director--had watched, and cared about, Classic Trek.
Karl Urban as Bones, for instance, uses exactly the same intonation and cadence as DeForest Kelly (as does Simon Pegg standing in for James Doohan). This is important. Accent alone doesn't do it--the speech patterns of the original have to be matched as well. (For instance, in the Stargate episode "Fragile Balance," Michael Welch does a respectable job portraying the young Jack O'Neill. The only thing he gets wrong is at the beginning of the episode where he is supposed to say, "Dan-i-el" in that annoyed way Jack has of saying Daniel's name. Welch doesn't peg it. The body language is on. The intonation isn't.)
Back to Trek, I must mention again how much I like Karl Urban (isn't he fantastic?! The guy can do anything; I mean, how different is this role from tense, taciturn, Russian mobster guy in Bourne Supremacy?!) and how nice it was to see Leonard Nimoy. What a gentleman!
The one casting choice I thought failed miserably was Sarek: the actor looks and acts nothing like Mark Lenard--not even remotely. He doesn't have the fundamental warmth or the compact dark intensity of Lenard. He doesn't have the right body language or speech patterns. He is totally off. I realize Lenard is dead, but really, people, Ben Cross would not have been my choice.
However, I did quite like Bruce Greenwood as Pike. The age is wrong (original Pike is much younger when captain), but I like Greenwood, so what the hey. Greenwood is a good example of accurate body language/good acting making up for an inexact visual match. (Again, Cross as Sarek bugs me. But then Lenard is one of my favorite Classics, and I miss him.)
Now that I've explored effects and characterization, here's what I think about the rest of the movie:
The plot is pretty stupid.
Sorry. But it is. Time travel has been SOOO overdone on Star Trek. I am also really, really, really tired of the type of villains used in the last three or so Star Trek movies. They look like they've all just arrived from a Queen's concert or something. They're young! They're bald and have tattoos!! They're very, very angry!!! Has Kiss contracted to service Star Trek needs for the next billion years or something? It is so entirely tiresome that I spent the first five minutes in the movie theater (waiting for my eyes to adjust), glaring at Nero, going, "Maybe it's a preview. Please let it be a preview."
Give me the Borg. Or Ricardo Montalban. Or some Klingons. Just no more revengeful young dudes who look like they should be strumming electric guitars, straddling motorcycles, and waggling tongues at adoring fans.
All that being said, if the movie is slated for television-dom, I'm on board. I don't mind the alternate history--Vulcan as a struggling, planetless race sounds pretty interesting as do Uhuru and Spock as a couple (by the way, the exchange on the transporter pad about her first name is CLASSIC Kirk-Spock: intonation, body language, everything). And if they could get Urban, I might actually have to hook up my digital convertor and go back to watching television full-time instead of just watching DVDs.