Pokémon collected within Black, White, and their sequels can be transferred to Pokémon X and Y, it has been confirmed.
Today’s scheduled Pokémon Direct saw Game Freak’s Junichi Masuda reveal that players will be able to download an application called Poké Transporter, which will work in tandem with Pokémon Bank.
With any of the Nintendo DS titles in your 3DS card slot, you can upload any gathered Pokémon to the cloud service from which they can then be transported into your Pokémon X and/or Y copy.
Game Freak’s Junich Masuda adds, “For everyone whose played the Pokémon series for a long time, I’m sure all the Pokémon you have trained are very important to you. So I hope you can take them with you and make them come alive in Pokémon X and Pokémon Y.”