Pokémon X and Pokémon Y director Junichi Masuda had revealed on his English blog on the official GameFreak website that a new battle mechanism will be used in the upcoming games. Below is his blog posting.

HIDDEN POWER of masuda - No.233 - 01.21.2013

We are aiming to deliver genuine entertainment that can be enjoyed simultaneously by people from all over the world.

Never-before-seen Pokémon that will be discovered for the first time by people from across the globe. Pokémon that are brought to life and look as if they are right in front you. Stunningly dynamic Pokémon battles. Breathtakingly beautiful visuals that take full advantage of the 3DS hardware’s power. An innovate communication system that will make you feel connected with players from around the world as you play the game. A new battle mechanism that allows your Pokémon to become even more powerful when the bonds you share grow stronger. A story and music that can be enjoyed by all.

Whether this is the player’s first game, or if he or she is a veteran of the Pokémon series, our goal is to deliver genuine entertainment that will make all players smile, regardless of their age, gender, country, language, or culture.

The Pokémon series has always been more than just a game. It’s a series that brings people together, and encourages them to get excited and have fun as if they were at a festival. That is why I wanted to achieve my long-time dream of a worldwide simultaneous release with these new entries to the series.

Pokémon X and Pokémon Y–the evolved sixth generation of Pokémon. Genuine entertainment that people have been waiting for is here. October 2013. I look forward to being able to play with everyone from around the world. Ciao!

Source: http://www.gamefreak.co.jp/blog/dir_english/?p=561