At this point I really think it is hard to say whether or not we will get to see the following feature return in Black and White 2, but I'd definitely love to see it again. If they do decide to have this, I somehow doubt it will only be with one Pokémon; that seems a little outdated. Still, it would be possible for them to transport the overworld sprites from HeartGold/SoulSilver and simply just create the new ones. If they were to use this feature again, I hope they would add a little more to it, but that's just me. Let's keep our fingers crossed!