Nothing, pokemon is always the same history...
you have 10 years and your mom let you go out of home and face a dangerous world to catch pokemons form nature and make them fight as slaves, you destroy the dreams of your rivals, you fight aganist any teams that wants to dominate the world, catch the legendary pokemon, well if it's legendary, why a 10 years old kid can catch him? and after this you defeat E4 and become champiom
Pokemon BW will not be different..
BUT, I REALLY HOPE THEY FIX THE PIXELS OF YOUR POKEMON BATTLE (battle sprites are awful in BW)