Just-in-time provisioning of Drupal user accounts based on SAML attributes (configurable). Automatic role assignment based on SAML attributes (configurable). Dual mode - support for traditional Drupal accounts and SAML-authenticated accounts at the same time (configurable).
"The Facebook OAuth module provides an API for executing queries against Facebook's vast store of user data." How does this translate into user experience (UX)? In extreme layman's terms, Facebook Oauth allows you to create custom buttons that, when clicked, will 1) grab some good facebook data, and 2) let Drupal interact with it.