How has B/W changed the metagame?

Fire was a pomegranate type in general in Gen 4 and no Fire-type Pokemon had Chlorophyll.

I was listing general boosts.

I guess I'll be more general:
rain dance > sunny day in that a single pokemon can get boosts 1 & 2, whereas the same thing isn't possible with sunny day.

But sunny day gives more boosts in general to a variety of pokemon.