Yessss!! Corocoro leaking!
~Mega Altaria is Dragon / Fairy and has Pixilate. Its Attack gets a boost. It's the exact same weight as before, but taller (1.5m vs. 1.1m).
~Mega Lopunny is Normal / Fighting and has Scrappy. Its Attack and Special Attack are improved. It's slightly taller and much lighter than before (Mega: 1.3m / 28.3 kg, Normal: 1.2m / 33.3 kg).
~Mega Salamence is Dragon / Flying and has Aerilate. Its Defense gets a boost. It's taller and a little heavier than before (Mega: 1.8m / 112.6 kg, Normal: 1.5m / 102.6 kg).
~You can get a shiny Beldum in the games.
~Pikachu gets special Pokemon Contest moves when you dress it up. Pikachu Rock Star gets Meteor Mash, Pikachu PhD gets Electric Terrain, Pikachu Pop Star gets Draining Kiss, Pikachu Belle gets Icicle Crash, and Pikachu Libre gets Flying Press.
It also confirms that when you change your Pikachu's clothes for contests, it gets special moves. Pikachu Rock Star gets the move Meteor Mash, Pikachu Ph. D. knows Electric Terrain, Pikachu Pop Star knows Draining Kiss, Pikachu Belle knows Icicle Crash and Pikachu Libre knows Flying Press