Amazon.com: Dr. Horrible’s Sing-Along Blog: Neil Patrick Harris, Nathan Fillion, Felicia Day, Simon Helberg, Joss Whedon, David Burns, Michael Boretz, Maurissa Tancharoen, Jed Whedon, Zack Whedon: Movies & TV Dec. 19th is the release date for Dr. Horrible’s Sing Along Blog DVD. Let the preordering commence!