Steam Introduces Paid Workshop Mods
Steam made an official statement saying that all modders for The Elder Scrolls V: Skyrim will now have the option of charging money for their mods. How much is up to the mod developers. Developers also have the option of using a 'pay what you want' system that can be set to zero dollars. Regardless of how much money the mod developer charges, Steam will take a 75% cut of all profits. Steam has also implemented a 24 hour refund period, for those who are dissatisfied with the purchased mod. Steam has not said if there will be a refund for mods that no longer work after a game is patched or when new mods cause current mods to fail.
Several popular Skyrim mods have already begun implementing the payment system. For instance, the popular 'Wet & Cold' mod now costs 5 dollars.
The decision to make mods purchasable for Skyrim seems to be a decision between Steam and Bethesda, so any future plans for purchasable mods on other games will likely be a decision between the developers and Steam.