After watching the trailer, there is going to be a LOT of speculation going on for the next two months.

The thing that stood out the most to me was:

The scene of the (I’m assuming) the lightsaber duel between Finn and Kylo Ren - in the scene Ren is seen from the rear, unmasked.
The hair style and color that we saw looked a whole lot like Anakin’s at the end of Revenge of the Sith. I wouldn’t put it past Abrams to have a Vader clone as the main antagonist.

Second thought - we have had three trailers now and have yet to see Luke Skywalker’s face.

Just food for thought.