As of right now, my team in Y is going to consist of:
Froakie's final evolution
A new Fairy Type (E.g something that wasn't retyped, and most likely it will be Sylveon)
Two interesting looking new Pokemon
Of the known Gen VI Pokemon, the two I find most interesting are Tyrantrum and Doublade, so those two are high on the list. Of course, this is subject to change after I get the game.
In X, I'm just going to Nuzlocke it, so planning my team is kind of irrelevant.