I've seen addons like CraftBot which advertise and allow searching of your tradeskills by other players. Looking at the trading functions, it seems like it would be possible to conduct the cutting/enchanting/tailoring/etc. automatically and then trade it automatically.
In other words, players would ask the addon whether something can be made, trade the reagent(s), ask for a product to be made, then receive the product back.
Is this possible, would it be violate the Blizzard ToS, and does it exist already?