Here's my experience. I largely stayed away from any news concerning Revenge of the Fallen. I was not active in the movie forums, I even stayed away from the threads about the movie's game. When the toys came out I got a few -largely because Windcharger called me and told me how awesome the Sideswipe figure was (he was right, too). So I did know some of the characters that I would see in the film. But the efforts paid off. I had no idea that Alice was a Decepticon (Pretender?). I had no clue towards Prime's sacrifice. The first time I saw that Devastator was in the movie was when I saw the preview during Star Trek and I was blown away. I had no idea there would be so many Decepticons. Seriously, I encourage everyone who reads this to stay away from spoilers for Transformers 3. I know I will.