The thing I find fascinating about the Star Trek movie is how it manages to utterly rewrite continuity, while staying in continuity. This is particularly apparent if you read the "Star Trek: Countdown" prequel comic book. That is pretty much in continuity, and is essentially "Next Gen: The Final Chapter", set 15 years or so after the end of the series. (I'm not certain that it resolves perfectly against every detail we know about the future of Next Gen, but it's reasonably true to it.)
And yet, by the end of the movie, it's simply not the same series. It's pretty much clear from the beginning of the movie that killing George Kirk changes all of history, albeit in gradual ripples. (Despite it also being clear that Destiny is a very powerful force in this universe.) Killing Amanda was downright startling -- the moment at which I realized that they were committed to breaking the rules. And destroying Vulcan qualitatively alters the Trek universe: it's a statement that, from here on out, you really can't count on anything from the original history.
The way it gets there is fascinating, though. On the one hand, it is *so* true to Trek, which has been obsessed with time travel since the word go: there's a real element of "live by the sword, die by the sword" here. OTOH, it breaks two classic meta-rules of the Trek universe. First, the general one -- "put your toys away at the end of the story". Even in the movies, they've mostly played by that: meaningful change has been unusual, and change in the *flavor* of the story downright rare. (Which may be part of why the franchise had started to feel a bit sterile to me.)
And second, the really specific one -- "you can change history temporarily, but in the end, it always gets fixed". After the movie, we were chatting, and someone remarked that they thought Spock was going to take the Jellyfish (that weird little ship, Geordie Laforge's masterpiece), and somehow pull a Superman with it: spinning the universe backwards and putting things to rights. And at the time, I was half-expecting the same: it would be totally wrong for the story, but so *very* Trek. And then, they simply didn't. The moment when the two ships collided felt like nothing so much as history setting in stone, changing permanently.
The result is downright refreshing, precisely because of the broken rules. There's a sense of not knowing where things are going next, that I've rarely if ever gotten from Trek before. It may well develop new well-worn grooves, but for the moment, I don't know what they will be. I suspect we'll continue to see homages to the old universe (heaven knows, they were laced through the movie -- I didn't even notice the reference to Admiral Archer's beagle until msmemory pointed it out to me), but for now, it can go anywhere. That's rather neat...