Mary Jane Watson was the most notable missing Spidey character from The Amazing Spider-Man movie. This will be remedied in the next two movies. Shailene Woodley has been confirmed as Mary Jane Watson. Shailene Woodley is most known for acting in The Descendants and The Secret Life of the American Teenager. (Via Screencrave)
It will be interesting to see how the weave Mary Jane and Gwen Stacy into the same story. Could it mean an eventual Green Goblin/ Spidey show down for the very life of Gwen Stacy? It would be interesting.
