Leaks for Pokémon Sun and Moon:
-trial Captains will be challenged in post game;
-there will be all new evolution methods for some new Pokémons;
-Alolan Pokémon that used to evolve with a Stone will now use a different new item called Alonan Stone;
-Dragonite and a flight of Zubats are rideable;
-Ash-Greninja is in game but not in the plot;
-Lillie comes from Kalos;
-Rival Hau has got an Alolan Raichu;
-Kangaskhan is findable in the first island, Melemele;
-Pokemon like Spearow, Pinsir, Gyarados, Magneton and Gastly are in regional dex;
-Komala evolves into a normal/psychic;
-there are a grass/fire berry Pokémon, a steel monkey Pokémon based on a typical bornean monkey and giraffe Pokémon;
-only first gen pokemon have alolan form (Alolan Gloom evolves in regular Bellossom);
-Rockruff can evolve in more than one Pokémon, the first evolution will be annunced in the first trailer of september;
-Hau and Plumeria can have a romance with the player, no matter the chosen gender of your character;
-there will be Alan from the Pokémon anime as a postgame challenge, if you beat him he'll give you a weird Charmander egg;
-Red and Cynthia will both return to fight the player in the postgame;
-HGSS's Safari Zone will return in order to catch non Alolan Form Pokémon and rare Pokémon Forms like Deerling's and Sawsbuck's;
-Poké Balls will be customizable like in DPPt using the PokémonAmie.