The latest feature to be added to Steam is the ability to pay for subscription based games through the Steam service. Gamers will have the ability to not only sign-up for subscription based games but also manage their subs through Steam.
The first game to take advantage of the new service is Adventurine’s PvP focused sandbox MMO Darkfall Unholy Wars. Not only can you get your hands on the game through Steam but you can now manage your monthly sub plans which should make like a lot easier for players of MMOs. Subs can be cancelled or renewed and payment methods can be managed through your account.
Currently Darkfall: The Unholy Wars is the only game to take advantage of the new system but rest assured many others will follow in the weeks and months ahead.
More details on how the system works can be found in the Steam FAQ.