Pokemon black and white, will their be yet another...?

do you think their be a 'middle game' as i call it, like emerald and platinum? a third game where you can catch both of the black and white mascots, they did it with ruby and sapphire (emerald) and diamond and pearl (platinum). so do you think they will have another black and white game with another random name (possible grey lol) where you can catch the two legendaries, i hope i'm making sense lol