Update: Via Deadline, here are comments from a statememt by Amazing Spider-Man director Marc Webb on Shailene Woodley's debut as Mary Jane being moved to the third film.
"I made a creative decision to streamline the story and focus on Peter and Gwen and their relationship. Shailene is an incredibly talented actress and while we only shot a few scenes with Mary Jane, we all love working with her."
Original story: Amazing Spider-Man 2 is set to introduce a lot of new characters to the rebooted franchise, but it appears that Mary Jane Watson will no longer be one of them.
According to various online sources including SuperHeroHype, Shailene Woodley disclosed in an interview in the print edition of the latest Entertainment Weekly that her debut as the character has been postponed until the third entry in the series, despite already filming scenes for next year's sequel.
"Of course I'm bummed," Woodley is quoted on the site. "But I'm a firm believer in everything happening for a specific reason... based on the proposed plot, I completely understand holding off on introducing (Mary Jane) until the next film."
The quote is from EW's cover story on Divergent, the film adaptation of Veronica Roth's popular young adult sci-fi novel, starring Woodley in the lead role. The article — and the pertinent MJ quote — haven't made it onto EW's website yet. In March, set photos and videos of Woodley filming Amazing Spider-Man 2 surfaced online.
Amazing Spider-Man 2 is set for release on May 2, 2014, with the third and forth Spidey films recently scheduled for June 10, 2016 and May 4, 2018.