leakfag here. I've spoken on condition of anonymity to several Japanese play-testers and members of the NOA localization team. What follows is all the information my sources were able to reveal about Pokemon Z.
>Pokemon Z is a New 3DS exclusive title in order to take advantage of the improved hardware. It's a safe assumption frame-rate drops are a thing of the past, and the game will boast a steady 60fps frame-rate.
>The battle and menu animations of all 722 Pokemon have been reworked, and assets from Pokemon Super Mystery Dungeon have been recycled for this game, presumably use as overworld pokemon companions to the player character.
>The timeline for Z is 3 years after XY, in an expanded Kalos with different encounters than those seen in XY, and an all new plot involving a resurgent team flare and the legendary Pokemon Xerneas, Yveltal, and Zygarde.
>The postgame opens Southern Kalos to the player, which contains a total of 6 new routes, 4 towns, and 3 dungeon areas. One of these new towns is home to a new Pokemon World Tournament featuring trainers from previous titles.
>12 new mega evolutions have been added to the game, mostly consisting of megas for favorites from the Johto and Hoenn regions. This brings the total number of Mega evolutions available in Z to 60. In addition to the new megas, the Mythical Pokemon Magearna will be unlocked in Z by an in-game event upon the transfer of your Pokémon 20 event Mew. This all-new Mythical Pokemon cannot be transferred to your XY and OR/AS game carts.
>an expanded Move Tutor system consisting of a guild in southern Kalos has revamped the TM system and the way certain TMs are learned. Move Tutors are analogous to gym leaders in Southern Kalos, and offer their services to the player upon defeat in battle.
>A new Pokemon Genetic Research Laboratory in Kiloude City will allow competitive trainers to sequence the genomes of their Pokemon and discover the Individual Values of their Pokemon team-members in an instant!
