The short version: Go see it. It rocks. Great for fans and non-fans alike, going to be huge, is doing for Star Trek what Casino Royale did for Bond, what Batman Begins did for the Caped Crusader. Absolutely fantastic film, going to do wonders for both the franchise and SF in general.
The long version: I've got too much personal history with Trek to watch it dispassionately. Once upon a time, I flew out to Los Angeles to take a course at UCLA on "writing for Star Trek" being taught by some old screenwriters associated with the original series and Jack B. Sowards of Wrath of Khan fame. That evening, I called up an old friend and asked her to dinner, but upon arriving at her house in Long Beach, found we'd both been invited out by her boss to a dinner at Mezzaluna's with the panelists from a "Digital Hollywood" conference. (As an aside, pretty sure Ron Goldman was one of our waiters. Sadly, this was one week before OJ.) I was seated next to Herbie Hancock, and didn't appreciate that then near as much as I would have now, but Brannon Braga was at the other end of the table, so I eventually made my way down to introduce myself. He was blown away that I'd flown out from Alabama to take the UCLA course and said he's put me on the guest list for his and Ron Moore's own seminar if I could come back a month later. I did. (Also in the class was Bryan Fuller.) I came back, took the course, and got on well with Lolita Fatjo (long time script coordinator on Trek). I left with a naive sense of how accessible Hollywood was and had moved out within about six months.
Cutting to the chase, I worked for Titan's Star Trek Monthly magazine for five years as their LA liaison, where I wrote over 500 articles and interviews with Trek and Babylon 5 cast and crew. I've spent hundreds of hours in the Trek offices, prop rooms, sets, cast trailers, etc... I also had a standing invitation to pitch stories whenever I liked and though I never sold any, pitched to Jeri Taylor and Bryan Fuller a few times. I left Hollywood at the end of 1999, disillusioned when the quality of DS9 dimmed in favor of the drek that was Voyager, and I didn't feel honest about promoting the show any more. I wrote The Making of Star Trek: First Contact across six frenzied weeks, but didn't really like any of the films after The Undiscovered Country, and never made it past the pilot of Enterprise.
So while Star Trek was a HUGE part of my time in Hollywood, it was also pretty dead and over for me in the 21st century.
And now it's not.
I thought the film was pitch perfect. I'm amazed that they managed a reboot that changed everything while disregarding nothing. This film absolutely takes into account everything that has come before, while firmly establishing that this is no prequel. I loved every minute of it, thought it was perfectly cast (was expecting Zachary Quinto to be the standout, but they all were good and I'm not sure but what Karl Urban's Bones wasn't the best). The film had the right combination of action, humor, adventure, seriousness, etc... I was surprised by the amount of screen time Leonard Nimoy got. I expected his role to be little better than a cameo and was impressed at how pivotal it actually was, and the best thing about the film is that it surprised me. Really, really didn't expect some of those changes. And for a 43 year old franchise to have any surprises is pretty impressive. What's more, the number of my friends who don't watch Star Trek, including one who has NEVER watched Star Trek before, who LOVED IT, is blowing me away. I think this film is going to be huge for erasing the lingering/already-on-the-way-out stigma of sf in general, and is the latest and largest nail in the coffin of the silly notion that sf isn't mainstream.
I came out last night at 12:20am so charged up I couldn't sleep. This morning, I find myself in another mood. Almost tearful at the way the past has been swept away. I remember reading the actual comicbook in which the golden age Batman died, and feeling a similar emotion. He wasn't my Batman -- my Batman was the Batman of Denny O'Neil and Neal Adams, who had never fought in WWII and didn't dance around on giant typewriters, and yet he was the original and he was gone. In the same way, this reboot exists for the 21st century, and for those who will carry Star Trek forward from this point. And I love that they acknowledged my Star Trek before they swept it away into the dustbin of alternate history. But this morning, I think I'll shed a tear or two for the future's past, for the end of that Star Trek I was personally connected to, even as I say to the new future, to the Trek my son and daughter will grow up on, "Warp Speed!"