"Classically movie studios don't make deals with director even if there's a hope that there's going to be 3 [films], because they want to make sure that you behave," Fincher explained. "But yes, the second two books are very much one story. It doesn't seem prudent to me to go to Sweden for a year, come back for a year, put out the second one, go to Sweden for a year, go back for a year."
It would come as no surprise that "The Girl With the Dragon Tattoo" will do well as it has already screened extremely well by the critics taking in a 94% fresh rating on RottenTomatoes.com. So expect to see more from Fincher and this series in the future.
Source: http://www.cinemablend.com/new/Dragon-T ... 28416.html