What I'd also like to see in the customization in Pokémon X and Pokémon Y is also the type of bag you'd be wearing, not just the hat, clothing, shoes and sunglasses. It would also be nice to see scarfs in the game as well, anything to do with accessories. Maybe even badges you could put on your character? And maybe even the Gym Badges you'd be able to put on as well?
There's a huge opportunity for many of those things to be implemented. Even some places may expect the player to be wearing certain things, most certainly to maybe even disguise as the evil team's Grunt or something, like how it was in HeartGold and SoulSilver in a way.