I have very little knowledge in programming or how video games are made, but I have had some very customization friendly games before, mostly dye-wise, but some pretty wacky combinations were allowed. (hot pink plate armor, e.g.)
How difficult is it to have a completely customized fashion system? For example, each piece of armor is consisted of three components, and you can mix and build your own armor, as well as dye it to the world's end. Much like the modding system, but with appearance changes.
Most likely not in this game, but would we expect this kind of freedom for creativity soon in the next-gen MMOs?