I doubt that a remake of G/S/C will be released, since you can get the G/S/C Pokémon in Colosseum and on the Islands in Fire Red/Leaf Green. I was hoping that Johto would be in Fire Red/Leaf Green, but it isn't, only Kanto and the Islands are in Fire Red/Leaf Green. So, I think that it is extremely unlikely that G/S/C will be remade, unless Nintendo makes another generation of Pokémon games sometime in the not-so-near future.