[Baltan II]

Not counting the Pokémon added to the postgame of Fire Red and Leaf Green, the version exclusives are definitely a bit different from Red and Bluie. The Meowth and Mankey lines were no longer version exclusive, while in an effort to reduce the overabundance of Water types in the wild, the Psyduck and Shellder lines were only in Fire Red while the Slowpoke and Staryu lines were in Leaf Green.

Heart Gold and Soul Silver weren't significantly different compared to Gold and Silver. The games made Omanyte and Kabuto's fossils version exclusives (using Rock Smash at Ruins of Alph) rather than being unobtainable outside of trades, but otherwise the exclusives were the same as Japanese Gold and Silver (US G/S accidentally swapped around the Teddiursa and Phanpy lines).

Omega Ruby and Alpha Sapphire will probably be identical to Ruby and Sapphire for Hoenn Pokémon, but as the Hoenn Dex looks to be revised to include other generations (see Lopunny and Audino) and only seven Pokémon are exclusive to each game, there will likely be new additions to version exclusives that add more variety between the two games.