I think the studio has complete confidence in whatever story that Nolan develops and will allow him to make the final film the way he wants to which is only a good thing for us fans. I chose Talia and Black Mask as villains for the third film because I think it circles back to the start of the film. Talia is the daughter of Ra's al Ghul and represents unfinished business with his mentor while Black Mask leads a rebirth of the mob. I would introduce Selina as a true romantic interest for Bruce. Rachel's death would affect him greatly to the point where he'd probably not seek out anyone but this mysterious Selina Kyle has caught his interest. Taila could potential be used in a triangle situation...have some kind of back story where she was off at college and only heard about Bruce in correspondence with her father (like in the novelization for Batman Begins) but grows fascinated by this man her father considered a possible heir.