Originally Posted by Fat Dark Arceus
Unless they have B2/W2 have backwards compatibility where they change the Pokemon to match what was available in black and white originals, it just wouldn't work. One of pokemons bases, as stated in an interview with the makers of pokemon, is the backwards compatibility between most versions. I highly doubt they would start a new or anything in b2/w2. To majorly change the game would make it incompatible with bw1 and ruin one of the main goals with pokemon.
It would certainly alienate the Black and White owners, but it's in the realm of possibility. Really the concern I had was type match-ups, which is within the constraints of what they can do while still providing backwards compatibility. Someone said Game Freak won't do that again, though.
I expect more mechanic changes to areas outside of battling. Things like partner Pokemon from HGSS, battle frontier, new breeding and EV mechanics, berries, non-Unova wild Pokemon present during main story, new forms, bigger distinctions between seasons, gym leader roster and gym design changes, and possibly the musketeers playing a larger role in the storyline seem plausible and welcomed imo.