Cheren, Homika, Shizui and Elesa are the only confirmed gym leaders so far. Do you think that there will be more new gym leaders? Plus, what happened to the first two gym leaders in Black & White? Should we expect a change in types?

There haven't been any information about the Elite Four, but Alder is still in the games. Will there be a change in the Elite Four, like a previous gym leader, who has become one of them?

Look at the Picture, you can see the badges in order from 1 to 8.
The ordered gym leaders:

Cheren, Homika, Burgh, Elesa, Clay, Skyla, Drayden, Shizui.

Credit to Serebii.

I'm still questioning what Cilan, Chili, Cress, Lenora, and Iris do. I've seen Brycen in PokéWood, but what wonders me is what'll happen to the replaced. And if the Elite Four get any reassignments, Pokémon or position.