Speaking with Game Informer at E3, Quantic Dream have sadly revealed that their second episodic download for Heavy Rain has been put on indefinite hold due to Sony encouraging the team to shift focus to the Move edition of Heavy Rain.
The first episodic content was dubbed The Taxidermist and let players experience some early investigation conducted by journalist Madison Paige. The second episode apparently let players actually play as the Origami Killer himself.
Quantic Dream's Guillame de FondaumiÃ¨re does mention that there is the possibility of the DLC going through the pipeline after the Move Edition is done; however, he states that the dev team will more than likely move on to their next project instead.
Source: Game Informer