Wasn't Dr. Horrible written bu Joss Wheeden?
The movie was written by Joss Whedon, his brothers Zack Whedon and Jed Whedon and writer/actress Maurissa Tancharoen (who is now married to Jed) during a Hollywood "writer's strike" It features Felica Day (The Guild), Neil Patrick Harris ( Doogie Hauser) and Nathan Fillian ( Firefly)
Lady V's description of "oddly watchable" is the best description I have seen of it.