When I watched the new trailer for the 1st time, at the very end of the trailer, I thought it was Sideswipe that was spinning in circles, cuttin sh*t up. Upon further inspection, I realized that it is actually Optimus Prime that is doing those spins and cutting into "something". He is very beat up and dirty, but it is indeed Optimus, with jet packs on his back, as you can see the jet packs falls off his back a split second after he lands and begins his spinning. The movement of the spinning reminded me of Sideswipe. But it is indeed Optimus, spinning, and cutting something up with his red hot blades.