I went today not expecting too much and I was a bit disappointed. My complaints boils down to "Less people more robots." You really couldn't get into the personality of most of the robots, especially with the Decepticons. At least the Autobots got a bit of non-combat screen time, but I really wanted to see Devastator be a brain-dead crushing machine and Starscream be the backstabbing ass-kisser he is. Oh yeah, and Hugo Weaving as Megatron? He's just become the go-to guy for everything these days and, as much as I like him, it's getting a little old. Last time I check, Leonard Nimoy was still alive. Not that he's the original Megatron, but he's close enough.
Of course, like everyone says, the action was great if a little too quick. They really did manage to give things a pretty good sense of scale and Prime turned out awesome. I guess you can't ask for too much more.