I didn't expect much and didn't get much. I disliked the two new autobots (Skids and Mudflap - never even caught their names in the film, had to look it up). Just thought they were silly.
The movie was overall entertaining other than the REALLY LONG ending. The action moved along pretty well, wise-cracks were pretty good. A little potty humor. Won't get any best actor awards but who expect that; the actors are in it for the money, not the art, and who is to blame them.
So my recommendation is to go see it with low expectations. You might be surprised and if you are disappointed, at least it won't be like I didn't warn you. :-)