An article at Variety.com confirms the filmic adaptation of "Sin City" and lists Robert Rodriguez (El Mariachi (1992), Spy Kids (2001), Once Upon a Time in Mexico (2003)) as the director.
Uh oh, I dont think he can do a dark film, but maybe he'll prove me wrong.
I think they should of got David Fincher of Alien 3, Se7en, Fight Club and Panic Room! they would be the awesome! ofcourse I dont even know what Sin City is but Im thinking its supposed to be dark and gloomy just like SE7EN!