Just like Gen V I want more theme pokemon. (Hero has dragons and samurai pokemon, etc)
But like BW2 I want all pokemon to be mixed in.
I want more multiplayer ability.
Like what they did with Platinum and the play area.
That was a fun idea, but I think more of that would be much more interesting.
Pokemon Following, of course.
That is such a fun idea!
Bringing back the rematch ability.
As for other games in it, I want to see a multi region side game.
Or full 3d with tales of symphonia/Spectrobes style fighting.
Tales of Specifically since, in my opinion, they perfected action-rpg game play.
Pokemon snap 2.
I can't think of anything else currently.