Would be nice if you could track your retainers. I mean stuff like:

- checking retainer's inventory (to see what you have there, I for one tend to forget what my retainers have)

- checking retainer's bazaar (to see if your items have been sold)

- retainer's would inform you by NPC linkpearl (or something like it) if you have sold anything

This would be a nice addition if FFXIV sticks with retainers. There is even a "Retainer List" in the main menu which serves no real purpose.