Those trailers look really good. I agree with everyone else that it seems they are really putting their FX budget to good use - at least, judging by the trailers.
The inclusion of Coulson reminds me a lot of the final season of LOST where they had the Man in Black take on Locke's form just so they could continue to have Terry O'Quinn on the show. Not a bad decision, I think, I'm just not holding out hope for some interesting connection between Coulson and this "new" enemy.
So Coulson has become the new Ward basically