Among Joss Whedon's greatest contributions to television has been the continual use of the Body Count, the willingness to kill off recurring characters in order to ratchet up the narrative tension and create a sense of danger.
In many television series, the actions of characters neither have long-term consequences nor cause long-term change. For Joss Whedon actions always have consequences and often change the show's narrative.
From the moment it first hit the Internet in the summer of 2008, Dr. Horrible's Sing-Along Blog received near universal acclaim as one of the web's first great creations. With Whedon proclaiming that his future work will be direct to Internet rather than TV, this could be the shape of Whedon's work to come.