Well, it seems Rourke wasn't ready -- in fact, he may not return at all. ComingSoon caught up with him at a junket for The Wrestler, and Rourke abruptly denied all of the above. "No, I'm not interested in that right now. That's not a reality right now. It's pissing in the wind. There's different factions going different directions there. I don't know. That's three hours of make up and I'm claustrophobic, so I'm going to have to work something out."
This is probably just Rourke being Rourke -- tomorrow he could be on board again, and tomorrow all Sin City 2 talk could vanish anyway. However, if he means it (and the make-up is something he brought up with MTV as well), that's not to say that Sin City 2 would be impossible to do without Marv. Any sequel was supposed to revolve around A Dame to Kill For anyway, where pre-Hard Goodbye Marv disappears about halfway in, so it is possible to comfortably write him out. Still, it would have been kind of fun to see a "midquel" onscreen, wouldn't it?