For those of you who don't know, Metroplex is a bad ass. He is a gigantic, city sized Autobot that can take out entire buildings with the swipe of an arm. According to Japanese Transformers lore he is over 800 meters tall (2,400 feet). Gigantic by any means. Him being in this game is just incredible for most Transformers fans.
The new trailer that was released on the Playstation Blog shows Optimus Prime calling on Metroplex to help him, even though he has never met the colossal Autobot. It shows Optimus ordering him to help and then shows Metroplex transforming into his robot mode and saying "Metroplex heeds the call of the last Prime." It is pretty dang impressive that the boys at High Moon Studios have decided to put him in this game. But it is only fair sine his biggest rival, Trypticon, was in the last game.
Here's hoping that in the 3rd game we get to witness the might that is Unicron.
Here is the new trailer titled "Through The Matrix" which refers to Optimus not knowing that Metroplex is there, but sensing that he is there through the Matrix of Leadership: