Marvel Comics Kills Off Major Superhero Character

This is a big week for comics, because in the pages of one book the editorial staff at Marvel pushed a major Marvel character into the realm of the dead. While death often isn't a big deal in comics, as characters can die and return within the span of just a few issues, this one seems like a big deal not just because of the character's identity, but the particular manner of his death means the effect could be more permanent than most.

For those who haven't heard about the specifics we'll keep them after the break.

Couple extra spoiler-buffering lines for those who might have avoided reports so far and could find this via RSS:
So: in issue #700 of The Amazing Spider-Man, Peter Parker dies. That's pretty big, but most major characters in comics have "died" at some point along the way, only to return sooner or later. But this issue sees not only the death of Parker, but a moment in which his nemesis Otto "Doctor Octopus" Octavius decides to accept the responsibility for Peter's life, and takes his place. More specifically, Doc Ock's mind now lives inside Peter Parker's body, and is (supposedly) determined to carry on his legacy as Spider-Man.
That's a big character change, and offers Marvel's writers and editors the leeway to make a lot of huge left turns in the Spidey storyline.
The bummer here isn't so much the fact of the story– with Spider-Man running continuously since the '60s in multiple comic book titles, there's only so much ground to cover, and every once in a while something really major has to happen. It's that, while reviews of the issue have even been kind, and the issue is a huge commodity at stores this week, that hasn't stopped the darker corners of the internet from sending death threats to writer Dan Slott.
Slott explained the storytelling angle to USA Today:
This is Moriarty in the head of Sherlock. This is Prince John inside of Robin Hood. This is the greatest villain inside the body of the greatest hero and trying to do good. This is a guy who was a couple steps way from a bucket list, and now he's got a whole new lease on life. That's really going to change him.
He also told CBR, that this finally puts Spidey in a place with the readership that he long occupied in the eyes of a character like J. Jonah Jameson:
He had to be a hero in his own eyes, and on some level Otto Octavius is facing that struggle not with Spider-Man's world but with the readership. How do you get more Peter Parker than that? Now the readers think he's a menace. That's exciting. On a meta level, that is Spider-Man.
This is all part of an effort that will rebrand The Amazing Spider-Man into a darker-toned book called Superior Spider-Man... until Marvel decides to flip the switch back. What the death threat-issuing dolts don't bother to think about is that the switch will be thrown once more at some point in the future. Parker won't stay dead, and Doc Ock won't always "be" Spider-Man. In the meantime, this is a ballsy, attention-getting change for the character, and might even be a way to tell a few Spidey stories that haven't yet been explored.