This trailer shows off the new Gyms and their redesigned Gym Leaders, along with two of the Elite Four. We can also see some more shots of Secret Bases and some new feature that lets you dress up Pikachu. I hope it's not just for him, I want my Swampert in a tutu!
And to top it off, we get to see some new gameplay of Mega Metagross. Serebii has some new info on it and Mega Diancie too, so check it out.