Pokémon Omega Ruby & Alpha Sapphire — 14 July, 2014

Nintendo have now confirmed details for Mega Metagross, which was recently leaked via CoroCoro.
Upon Mega-Evolving, it gains the abilityTough Clawsand remains Steel/Psychic type. Its Speed is greatly increased, but also has small increases in each of its other stats too. More pictures and video below.
Also confirmed are some gym leaders and Elite Four members. These are the same as in the original games, but we see that Elite Four Phoebe uses a Dusknoir, Elite Four Sidney uses a Shiftry, and Champion Steven uses Mega Metagross.
New games Pokémon Winds & Pokémon Waves announced!
Pokémon FireRed & LeafGreen to be re-released on Switch, and Pokémon Presents upcoming
Alpha Charizard distribution announced in DLC launch trailer
Mega Chimecho & Mega Baxcalibur revealed in new trailers for Mega Dimension DLC
Mega Evolutions for Raichu and the original Kalos starters announced
New game Pokémon Pokopia revealed in Nintendo Direct
Z-A Battle Club revealed at Pokémon World Championships