The Twitter Streaming API has been successfully used by Yahoo!, Google, and Microsoft, who have been given access to the full feed of all public tweets. Twitter has now enabled this "firehouse" of data for a number of other companies.
Facebook has announced that it will soon upgrade Graph API v2.3 users to v2.4. The automatic upgrade will take place on July 10th as part of Facebook's 2 year deprecation cycle. Significant changes from v2.3 to v2.4 require pre-migration attention from developers to avoid app disruption.