Taking to the SXSW stage to discuss the initiatives of his Quickdraw Productions company, Rodriguez also commented that Sin City 2 will begin production later this year, most likely over the summer. He remained silent on the cast but did indicate that the targeted actors will be of the same caliber of the first film, which featured Mickey Rourke, Bruce Willis, Jessica Alba, Clive Owen and Josh Hartnett.
Whether that means he's targeting the same actors or going after a fresh cast is anyone's guess but that's likely what Rodriguez intended with such a cryptic answer. I think the real question here is that after such a long gap between the first film, will a sequel still have the same appeal with moviegoers given the current state of what media outlets like to refer to as "comic book adaptation fatigue."
It's long been thought that the sequel will look to take it's cues from Frank Miller's A Dame To Kill For. Oscar winning writer William Monahan (The Departed) is writing Sin City 2 alongside Miller and Rodriguez.