Hey. I'm currently doing a hack for Pokemon Black 2 which will include the whole Sinnoh region, Pokemon, trainers etc. Something like Pokemon Platinum in Gen 5.
Main Features (all the features will be listed later)
story, characters and locations from Pokémon Platinum (+ some characters from other regions )
National Pokédex from the beginning
Pokémon from Kanto, Johto, Hoenn, Sinnoh and Unova are obtainable
moves and abilities from generation 5
boosted weaker Pokémon stats, moves and abilities
"improved" some bad or annoying things from Platinum