That said, there are some pretty massive bullsh*t moments to swallow. Like a mining vessel being able to fend off several Starfleet spaceships and the Earth being left completely defenseless in the process.
If you're interested, you can look up the series of four comic books they released to lead up to the movie - they're called Star Trek: Countdown, and it's basically the story of the stuff that Spock was telling Kirk in the mind-meld. Part of what they explain is that after the destruction of Romulus, the mining ship is retrofitted with some technology that was reverse-engineered from the Borg, which is what made it so formidable. I'm not sure which came first - the movie, or this little backstory, but some part of me believes that someone wrote this to fill in the plot holes after the movie was finished. :P
My feeling on the movie is: I think it injected some fresh blood in to the franchise. Sure, they could have written the same plot with completely different characters and not made it a Star Trek movie at all, but this is hardly the first time that a series or franchise has been "re-imagined" in order to bring in as broad an audience as possible (Battlestar Galactica comes to mind).
I consider myself a Trekkie, but in my opinion the franchise has been stale for years. They can't make any more movies with the Next Generation cast; they wrote most of the characters off the ship in previous movies and other canon. Enterprise was a flop and got lambasted by the fan base for messing with continuity too often. You could put together a whole new crew, a whole new ship, set it within the same time frame as any of the other shows or movies but in a different location (thus preserving canon by simply avoiding it), but then calling it "Star Trek" is even more of a stunt than it was for this movie.
One way that Star Trek differs from Star Wars is that it (Trek) has a lot
more material that the canon is based on. Star Wars had three movies and a handful of other media (books, games, etc.), so making the prequels was less troublesome from a continuity perspective. Trek has multiple shows with multiple seasons, movies, comic books, etc., and legions of fans that know all of it backwards and forwards. If they wrote a scene in which Kirk sneezed, some dude somewhere is going to pull up some obscure reference to why it never should have happened.
At one point in the film, Kirk tells future-Spock that going back in time and changing history was "cheating." So, yeah, I think the filmmakers knew that. But I also think that this gives them a lot more creative license for sequels or whatever else comes next. They can keep the iconic characters, keep their personalities and relationships, but give them new adventures without completely
trampling everything people know about Star Trek.