Casting : Patrick Dempsey (Derek Shepherd), Ellen Pompeo (Meredith Grey), Justin Chambers (Alex Karev), Katherine Heigl (Isobel "Izzie" Stevens), T.R. Knight (George O'Malley), Sandra Oh (Cristina Yang), James Pickens Jr. (Richard Webber), Chandra Wilson (Miranda Bailey), Isaiah Washington (Dr. Preston Burke, Kate Walsh (Addison Montgomery-Shepherd), Sara Ramirez (Callie Torres), Eric Dane (Mark Sloan)...