USA Today on Bay re: the dead in Transformers 3.
...Michael Bay and Co. acknowledge missteps with the last one and aim to upgrade the shape-shifting robot franchise with a more coherent story, less goofball humor and a pledge that characters who die will stay dead.and
While Optimus Prime, Megatron and even Sam all have died and been resurrected, di Bonaventura says this film will have no do-overs: Die, and that's it.
The dead will stay dead... Certainly a step toward a 'more coherent story'.