L’Heureux told the site that the Sin City sequel will go into production in the second half of 2010. The sequel will be based on an original script by Frank Miller, who will again co-directed with Robert Rodriguez.
The producer added that Miller is working on the screenplay for Hard Boiled, based on his and Geof Darrow’s comic about an insurance investigator-turned-cyborg assassin. Miller is attached to direct the adaptation.
Because Sin City 2 will take up Miller’s time for a while, Hard Boiled could take a while to hit theaters. “There’s also talk, of course, of ‘Sin City 3′,” he said.
Source: Comics2Film at Mania.com