I just thought about this. Since Black and White is a new beginning, and a whole new world set aside from previous generations. There has to be more generations of new Pokemon ahead! Because there is not only gonna be one region(Unova) in this new world, that woulden't make sence. So i'm thinking that the next generation's Pokemon will be based on the second generation. Because generation 5 is based on 1st generation, here is more of what I am talking about....
New World
5th gen Pokemon-Based on 1st gen Pokemon
6th gen Pokemon-Based on 2nd gen Pokemon
7th gen Pokemon-Based on 3rd gen Pokemon
8th gen Pokemon-Based on 4th gen Pokemon
....Then if Pokemon continues, there will be a another new world.
Do u get what i'm saying?
New World
5th gen Pokemon-Based on 1st gen Pokemon
6th gen Pokemon-Based on 2nd gen Pokemon
7th gen Pokemon-Based on 3rd gen Pokemon
8th gen Pokemon-Based on 4th gen Pokemon
....Then if Pokemon continues, there will be a another new world.
Do u get what i'm saying?