Well, hypothetical question asker, if I can cut through the sarcasm, I know what you are getting at. Yes, I did see Watchmen on the opening weekend, but no, I didn't stand in line to see the Thursday midnight showing.
I liked the movie very much, and I want to point out a few things to people who might not have seen it, just so they know what to expect.
The movie is long and though things are cut out of the original graphic novel on which it is based, it stays very true to the story. Many scenes look like the storyboards were taken directly from the pages of the graphic novel, and dialog is lifted line for line.
Watchmen is a Big Shit Blowing Up movie (which my friends and I have shortened to B.S.B.U. movie), so you will miss a lot if you decide to rent it and watch it at home, unless you have a super duper home theater. Some people might want to see it in IMAX. IMAX just makes me tired. I can stand about an hour of The IMAX Experience before the law of diminishing returns kicks in.
Watchmen is rated R, and if a film board was doing its job, it could easily be NC-17. It's very violent and there are a couple long sex scenes, shot by shot re-creations of scenes in the original book. Definitely leave the twelve year olds at home.
All the major characters from the book are in the film, and for my money, the one that translates to film best is Rorschach, the costumed crime fighter who has stayed out on the street after the government has banned costumed heroes. Played by Jackie Earle Haley, Rorschach and his former partner Nite Owl are like the dark and light parts of Batman split into two characters. Nite Owl is the rich guy who loves the gadgets and is committed to serving the public. Rorschach is the brilliant detective with a psychotic and uncompromising need for justice. While there is plenty of violence throughout the movie, Rorschach's scenes are particularly graphic, so be forewarned.
A major plot point of the book and movie is the introduction of Doctor Manhattan, a true super being thrown into a world of costumed crime fighters. Like in many comic books and sci-fi films, Doctor Manhattan becomes super powerful as the result of an atomic accident. He was a physicist before his transformation, and now that he has the power to alter matter at the atomic and sub-atomic level, his interest in humanity is minimal at best. As a visual cue that human rules do not apply, Doctor Manhattan spends much of the movie walking around naked, so you get to see a lot of blue butt and blue penis, or as my friend Jodi calls it, Lower Manhattan.
I gave a very negative review to Slumdog Millionaire for being too violent and now I give a very positive review to Watchmen, which is just as violent, if not more so. For me, the violence alone is not the criterion for liking or disliking a film, but how it is used in the furtherance of the story and if the story is worth telling. For me, Watchmen is a story worth a couple hours of my time, but as I told hypothetical question asker earlier, I'm a pretty big nerd.
Your mileage may vary.