It won't. Marvel put a gaping wound in the character of Gwen Stacy by letting that story be published, and it'll remain there so long as Marvel wants to pretend it doesn't exist instead of dealing with it. Kind of like with One More Day. "Why can't you just get over One More Day?" Marvel asks. "Because One More Day was a fundamental betrayal of the character of Spider-Man, just as Sins Past was a fundamental betrayal of the character of Gwen Stacy," I answer. That's the problem; we have all these world-shattering comics that betray what we know and love about the characters so depicted, and it's allowed to happen because Marvel is more concerned with "making an impact" than it is with character fidelity, which makes the characters, the stories, and the fans and readers suffer for no good reason. Until that actually gets dealt with, stories like Sins Past and One More Day will never die.