I would like to see aesthetic ship customization, primarily where SKINs are concerned. As I envision it, customization would be similar to what currently exists for characters.
Players could dock at a station and customize their ship. It would come with an associated cost. Perhaps alliances and/or corporations could purchase or earn the right to create their own SKIN, and offer it at a cost or free of charge to their members or the general public.
Similar to the SKIN licenses already in place, they could be bought and sold on the market. Essentially what I envision is what we already do for characters, but applied to ships, with an associated cost for repainting those massive hulls.