Heavy Rain was announced way, way back at E3 2006, which was the week of May 8. One week after the show, May 15, 2006, the U.S. Copyright Office recorded an option for the film rights to the game.
The option, re-filed in 2007, is between Quantic Dream chief David de Gruttola and New Line Productions. By itself it doesn't mean Heavy Rain is coming to a theater near you soon. Short form options are simply a notice that the rights to produce an adapted work have already been granted. It's largely a procedural matter, one that sets for the record who owns what rights.
But it's fascinating to see that, so shortly after the game went public, Quantic Dream had a Hollywood option for the game. It means they were either in talks well before this, or there are (or were) Hollywood types roaming E3 with orders to snap up rights to promising-looking games. Hollywood has tons of money, and options are often bought up as a hedge, comparatively cheaply, very early in a work's life cycle. Because they get hellaciously expensive when they get popular. So the latter scenario's somewhat plausible, too.