I think Marvel has to be careful with a Black Widow movie, since in the past female superheroes don't fare well in their solo efforts (Supergirl, Catwoman, Elektra, etc). Even though ScarJo is a well-known Hollywood actress who can headline her own movies, it doesn't guarantee that BW will be successful. Marvel should put this in the back burner until The Avengers and perhaps even Iron Man 3 were made, and they should treat this movie as seriously as they did for their other tentpole movies, and not do what Fox did to Elektra.