Well, a couple of things worth noting... I was reading Spider-man comics when this story line came out in the early 70's. And I have to tell you, there was a huge outcry from fans. No one liked the taste that death left in their mouth, even though Norman was killed in the process. The poetic justice did not leave anyone feeling particularly rewarded. And for years following, fans demanded that she be resurrected from this fate. Of course decades after it's initial release, I think it has been homogenized as just another storyline in Spiderman's history. And for those of us who read it new, many are repulsed by this idea that Marvel decided to spare Norman Osborn later on and make Gwen even more of a victim by having him rape her too. So, in many ways, killing her AGAIN would be very bad form in retrospect to the whole history of the character. To me, this is a chance to right certain wrongs. Spare Gwen and let Norman die. And for the general public who knows nothing about this character's history, I would say it would be risky to kill her off since she was one of the most-liked characters in the retelling. That would be depressing for a summer film and turn people away to additional viewings.