Another idea popped into my head. What if the Fallen is in the movie as a herald of Unicron? The movie might have some explanation of TF mythology at the beginning and the Fallen is a possible sleeper sent by Unicron to susceptible worlds for devouring. Since it appears Megatron is a tank in this movie, much like Galvatron, perhaps the purpose of the Fallen is actually to create an army for Unicron from the fallen TFs on earth, much like Unicron reformatted Megatron. I doubt we'd see Unicron in this movie but its a possibility for a future film. I know Bay doesn't like to set up for sequels, but in the first film he left the door open for Galvatron, he sent Starscream into the atmosphere, and he got Optimus to send a beacon into space. Those sound like set ups to me. Just my mind sputtering away... thoughts?