Pokémon X and Pokémon Y

Some people think it might be a light-type, the reverse-type of dark.
I wouldnt' mind that at all, honestly.

Make plant-types immune to it(photosynthesis, durr).
Make it and dark deal super effective damage to eachother.
And well, light-based attacks probably wouldn't be too hard to think of.

But the Dark type isn't the dark you're thinking of. Like, I get what you're saying and I thought that too but the current Dark type is supposed to mean like "dirty/sneaky fighting" which is why Fighting is super effective against Dark. It doesn't mean Dark, as in shadows and vampires and pomegranate. That's more of a Ghost type.