Pokemon Black and White's director wants to put old and new players on the same level.
Pokemon Black and White, coming out in September in Japan, will feature only new Pokemon until the end, according to Junichi Masuda, the game's director, in a blog post on developer GameFreak's web site (translated via Andriasang).
Masuda explained that he wanted kids and adults to start at the same place in the new game, so everyone could have the sense of discovery with new creatures.
He also shared some quotes from people inside and outside of the company that have played the game that showed that the new pair of games hearken back to the days of Pokemon Red and Blue, as players didn't know what type each Pokemon was and commented on how new it felt.