Like all previous Generations of Pokemon, I'll plan on obtaining all three, and in the unlikely case of a Generation III remake, I'll probably get those, too. (though I don't really foresee those happening for a while, if at all)
Currently, I only have the Japanese version of Pokemon White and will only get Pokemon Black when it comes out over here. Hopefully some American copies get sold over here, though... because I'm terrible at waiting for European release dates... at least unless its only a matter of days between them. xD I do believe Pokemon HeartGold and SoulSilver were like that; I actually waited for them to come out in the UK, for a change... but I did have a Japanese copy of the games, as well. ^^;;