I'm not disappointed in the traditional sense. It could have been better, but I think anyone expecting to see anything close to the level of the OT was just fooling themselves.
I thought it was exciting, and there's almost no way it could be as bad as the prequels.
I won't be able to say more until we see more, but for now, I'm cautiously optimistic. It's a teaser trailer, and boy were we teased.