You CANNOT tell me that "Daughters of the Dragon" would not look kick-ass on the big screen with two female leads. Not to mention the fact that the film has the potential for BOTH kung-fu and gun-fu action. And it doesn't hurt to have an Asian-American for one lead and an African-American for another.
But I think a lot of female comic book characters have been hurt by the failures of Catwoman and Elektra. Which, in both cases, it wasn't the fault of having female leads it was the fault of having really, really, REALLY poor scripts... But that's not what studio execs are going to take away from it.
I think it's going to take someone making a really GOOD comic book movie based on a female lead before the studios will run out and take a chance on more.