Ok, erichcollins already hit the nail pretty much on the head for this one, but I’ll do a quick review as well, mostly because I just saw the movie and it kicked some major ass.
As predicted, Live Free or Die Hard was the best action movie of the summer....for one week. Now, I say that knowing full well that some people will not be into giant alien robots that transform into human vehicles, so some will still prefer Die Hard. However, Transformers is the quintessential big budget, huge special effects, blow 'em up, shoot 'em up, 4th of July movie.
The movie has a serviceable plot. Essentially, the Transformers are aliens from the planet Cybertron. After the evil Decepticons, led by Megatron, take over and destroy most of the noble Autobots, led by Optimus Prime, the race of living robots begin to search the galaxy for a cube that is the source of their power and life. Obviously, the cube is on Earth, and the battle quickly ensues to gain control of the cube to be used for evil or good. Shia Lebeuf plays Sam, a high school kid who holds the secret to the location of the cube, and he's joined by what is actually an interesting cast for such a visual effects vehicle. Megan Fox plays the hot girlfiend, Josh Duhamel (Las Vegas) plays the Special Forces Soldier that leads our primary resistance effort, John Voight plays the SecDef, and John Turturro plays a comical super secret govt agent. The acting is decent, by which I mean that it isn't distracting from the rest of the movie like you sometimes get with big budget thrillers. The movie is PG-13, mostly for violence, although there is some sexuality. I was surprised to see very young children in the theater (2-4), but was not surprised at the rest of the audience which seemed to include kids who are just discovering the Transformers as a new toy franchise, and their parents who grew up with Transformers as a cartoon and toy. Although the characters don't exactly match the originals (for example, Bumble Bee is a Camaro instead of a Volkswagon Beetle), all the basic stuff is in here, including lots of the original style sound effects, and even the original Optimus Prime voice actor. The effects are some of the most amazing I've seen, and the cinematography is really good, although there are a few times when there is just too much going on on screen to really sort it all out, and the blatant GMC product placement might make you shake your head for a second or two. The violence is generally non-bloody in nature, but big and loud, so if you plan to take kids, take that into consideration. Overall, this was a really good theater experience, and will certainly make huge money when it comes out in hi-def DVD. Leaving the ending open to sequels, this franchise will certainly squeeze a couple more movies out over the next few years, and is bound to make tons of cash over the long semi-holiday weekend. If you're passing the time between torrential rain storms like we are in South Texas, or if you just want a really cool action effects thrill ride, or if you just feel some nostalgia for the tos and cartoons of your youth, I highly recommend this movie.