There's a chance that Spider-Man fanboys just out-geeked Marvel Enterprises.
A recently released set pic from "The Amazing Spider-Man 2" shows Emma Stone (as Gwen Stacy) in an eerily similar outfit and pose from a comic book in the 1970s. The one in which Stacy dies.
The photo shows Spidey swinging with Stone in a sea-foam green trench coat, purple skirt and black boots. Guess what Gwen Stacy is wearing when she dies in the comic book? Bingo.
Also read: Chris Cooper Cast as Green Goblin in 'Amazing Spider-Man' Sequel
Gwen Stacy died in "The Amazing Spider-Man" #121 in June, 1973 at the hands of the Green Goblin. In the comic, and in the 2002 Sam Raimi film (you know, the one with Tobey Maguire as the webhead), the Green Goblin dies when he's impaled by his own glider.
Remember, "The Amazing Spider-Man" is not a continuation of Raimi's "Spider-Man" but rather a reboot of the franchise. So Norman Osborne — who is the Green Goblin — is back in, this time played by Chris Cooper. And Mary Jane, Spidey's other love, is in the film too via the casting of Shailene Woodley.
What does that all mean? Marvel either just gave away a key plotpoint, or they're messing with the fans.