Some kind of wardrobe system that would allow different costumes that we could show to others and flip between the different costumes via the character "screen" or whatever. One of the ways to differentiate yourself would be visually. These could be just visuals and not necessarily actual combat gear.
Also, and I'm uncertain how this "works", there may be (and probably will be) a difference between the top-level map vs the 3d instance area. I'm curious about how the visuals will be at the top-level map whether this would or could even apply.
I don't see why they couldn't just put the same 3D character on the overland map. I would like there to be a preview of what an item would look like on your character before you purchase it from a vendor.