I believe the 4th film will fill a hole during the cold war era, remember the decepticons are already on earth conspiring with the humans. This wouldn't require the current characters to return, and while Optimus and his team are currently looking for the allspark cube, this could also introduce a whole new band of autobots looking for the cube and the decepticons as well, possibly introducing Ultra Magnus as Commander. Remember the decepticons are also gathering forces on the moon as well, which could introduce a whole new band of decepticons, this could give Starscream the oppurtunity to lead the Decepticons as Megatron is frozen on Earth. Remember in every movie the autobots have come out victorious, this could also give the Decepticons a turn at victory and give balance to the movies like Lucas did with Star Wars.
it would be better if it was a second trilogy, and the characters are from the armada trilogy and seasons 3 and 4
I am thinking,make it this time round,all Autobots are being defeated terrible no matter what ways they tried to defeat Decepticons, story to be continued in TF5 as per how Autobots rise from the fall of their defeat from TF4
the combaticons are a good touch but only as supporting villains, there are only two descent enemies to replace megatron, nemesis prime or unicron!
