I liked it. Fun, good characters. Unlike Sommers' Mummy movies though, the characters didn't get enough time to interact in in amusing ways.
The end of the film went a little umm, weird on me.
[sblock]O.k. First, what's up with the blowing-up the ice cap? Ice floats, so nothing should have sank. In fact, it would make getting back up to the surface easier if something went wrong. Second, if the ice cap is blown up what were the elevator cables attached to?[/sblock]
Character recognition was strange. Cobra Commander's character was changed enough in the movie, I actually mistook him for someone else until. That said, it was kind of cool going through the movie going "hey, its _______!"
All in all, average. Though, and I never in my life thought I would say this (let alone twice in one summer) it wasn't as good as the first live action Transformers movie.