After thinking about this for a good while, I'm actually fairly doubtful that character customization would make it to the games.
Reason being is that, if it did exist, I'm sure that we would've at least seen some screenshots of the main heroes in different costumes of some sort. u_u I was thinking about it, and then I realized that the hero was pretty much in the same clothes throughout all of the screenies, so maybe there won't be character customization, and instead the whole "main character looking in the mirror" scene was in fact something else? I dunno, but I'm not getting my hopes up or anything, as much as I would want this to become a reality.
I'm hoping that in future screenshots, they would show the heroes in different clothing to prove the character clothing theory, but until then I'll keep being skeptical about it.