The original Transformers movie was a unique mixture of realistic, intense action and child-like play (as examples, recall scenes where the military first encounters a decepticon invader and contrast that with autobots hiding from Sam's parents in his back yard). The film was carried by its teenage protagonist, Sam Witwicky (Shia LaBeouf), and featured a personal relationship with his Camaro friend, Bumblebee. This film was extremely popular, and I was really looking forward to the 2nd installment. However, I was pretty disappointed.
What is so sad is that this movie really did have some amazing special effects, but when effects are matched to a witless plot, they can't save a doomed film. I wish I could explain to you what the point of the movie was supposed to be, but I can't. To me it seemed like I was watching someone else play a video game...for 2 hours. The characters had no real connections with each other, except that many of them were from the first movie. For example, Sam's girlfriend (Mikaela Banes) has no real business in this film, and why she would be attracted to him is perhaps the most outlandish part of the whole plot. He is portrayed as the nerd with no confidence while she is the goddess who knows she's hot. The rest of the characters are equally as moronic - it seems that no one behaves in this film as a normal person would. In fact, the robots seem to have more sense than the humans. As for the battles and conflicts that occur, the only real explanation seems to be that the autobots are the good guys and they fight the decepticons who are the bad guys.
Although the effects are quite impressive, I do have one complaint. The transformers "transform" so quickly (in less than a second, it seems a car becomes a robot warrior or vice versa). I remember the old cartoons from when I was a kid. Those cartoons made a big deal about the transformations, and if you had your own toy you could transform yours along with the show. I believe that this slower pace also made the transformations more authentic because it showed how the vehicle and robot warrior were made of the same parts...in other words, the engineering on these things was plausible. In the film, however, it goes so quickly that I think they really pull a fast one on you in that they just show a car, then some blurriness, then a robot warrior...
All in all, die hard fans will still get something out of this movie. However, those who were surprisingly impressed by the first may be horribly disappointed by the second. Will there be a third? Of course! Simple economics demands it, although the box office numbers of this sequel are more attributed to the popularity of the original than the merits of the sequel.
I wouldn't bother. This is one of those movies that makes you dumber just by watching it.