I saw it this afternoon... and I really enjoyed it. Of course, I'm not a G1 nerd so I wasn't disappointed in some of the changes.

It was kind of fun to hear Optimus Prime's voice again (like Scotty, I was a wee lad whence I last watched an episode of TFers). I loved the Autobots and I really enjoyed the cheesy parts as well (such as all the 'bots hiding in the backyard).
I'll also agree with some of the thoughts here in that the transformations were badass - those effect do deserve an oscar for the way they carried them out. When Bonecrusher and Prime transformed on the freeway to battle, it was totally geeky and I loved it.
There were some parts they could have cut to make the movie shorter (stuff with the dog, looking for the glasses), but it was still a lot of fun.