At YourTrove, a lot of what we do involves ingesting social content via APIs and then regularizing that data within our system. For a lot of data, this is pretty straightforward. For example, while Facebook and Flickr might return different meta data, or name fields differently, no one disagrees that a photo is a photo. This is true for essentially all uploaded binary user generated content.
Facebook is starting to approve additional "actions," verbs that let users go beyond Like. Developers can use Facebook timeline actions via the Facebook Graph API, but only if approved by the social network. Social shopping platform AddShoppers received approval for "want" and "own" and even has some Like-like buttons for those actions.