It appears quite likely that Sony and director Marc Webb are planning to build the sequel to their successful revival of The Amazing Spider-Man around the death of Gwen Stacy, who is played by Emma Stone.  The leak that led to this conclusion was included in a recent story confirming reports that actress Shailene Woodley, who starred with George Clooney in The Descendants, had been offered the role of Mary Jane Watson (see "Shailene Woodley to Play Mary Jane Watson").
 
In an article about Woodley snagging the lead in an adaptation of a popular YA novel The Divergent, The Hollywood Reporter noted that she would have time to play The Divergent part because "the Mary Jane role is proving to be only a very small part in The Amazing Spider-Man 2 but blossoms into an integral lead for the planned third movie as the studio seeks to make the classic "Death of Gwen Stacy" story (for the sequel)."