Transformers finally made it to Japan this past weekend so I checked it out tonight.
I don't know where all of these complaints about it being such a bastardization of the original series are coming from. Like with most of these adaptations of past comics, TV shows and the like, or novel adaptations for that matter, people can't seem to deal with the fact that there are going to be liberal alterations from the source material to update it for present-day audiences and to tailor it to the film medium. As has been said in this thread and others, the cartoon was basically about good robots and bad robots fighting each other and blowing up stuff in between them, which is basically what the movie is about. The show tried to further humanize the story by showing the relationship between a boy and these robots; the movie does the same.
It's obvious the movie was NOT targeted solely for people who grew up enjoying the cartoons, otherwise there wouldn't have been the radical design changes. It's also obvious that this is not the only audience the movie has drawn, given the box office numbers and its relative longevity.
Anyway, I thought the story was established nicely from the start, and I enjoyed the humor although it certainly relied on cliche at times. Certain alliances are drawn a bit too hastily and from that point on the movie begins to lose plausibility, but we are talking about giant transforming butt-kicking robots here, what do you expect. With the exception of one character the robot effects were fantastic, as was the action. I'm not the biggest believer in ILM but I have a hard time imagining such a daunting effects job being pulled off any better. Was also impressed with the robot voices, which although different from the originals in most cases were faithful in spirit.
There were definitely plot holes but many of them may well be addressed in a sequel, which I am looking forward to.