Its official, Steam Trading Cards are coming to .. Steam.
Once you’ve collected a set of cards you can craft them into a game badge. Like the current badges, they are tied to your account and are shown on your profile. Unlike the current badges, crafting games badges earns you marketable items like emoticons, profile backgrounds, and coupons. Level up your badge by collecting the set again and earning more items.
Get rewards for crafting badges
During badge crafting you’ll receive random rewards from a set of game related items. They are tradable and can only be used while you possess them.