Katherine Senzee (aka ksenzee) talks about the Drupal 7 Admin Overlay which she helped get into core. She talks a bit about the controversial feelings that people have about it coming from site builders, and her own thoughts and feelings on it evolved over time after working with it as a site administrator. She talks about some of the architectural decisions that were made in implementing it as well as some of the new Drupal 7 hooks that it is leveraging. Senzee also discusses some of the ongoing accessibility implication of the overlay as well as how contributed module developers can integrate their menu local tasks into the overlay with the hook_admin_paths() function.