Amazing Spider-Man #699-700
Doc Ock is in, literally, his final hours of life. Through the use of the deux ex machina of "Octobots", Ock switches bodies with Spider-Man and begins living as "Peter Parker", even getting back with Mary Jane. Meanwhile, Peter is trapped in Doc's old body and does his best to fight his way out.
Peter's able to recruit Scorpion, Hydro-Man and the Trapster to help him, with the ruse of "Doc Ock" paying them 6 million bucks. "Spider-Man" is always one step ahead of him and Peter can't get a break.
It all culminates in issue 700 with a pretty big event..... so SPOILER space is being added (click away now if you don't wanna' know):
"Spider-Man" puts the entire supporting cast (MJ, Aunt May, JJJ, Jay Jameson, Horizon Labs goons, even Glory Grant) in a safe house and waits for "Doc Ock" to arrive. Doc's frail body is falling apart by the second, but he manages to grab Spidey and fall out a window.
In a final effort, Peter makes a connection with his memories...which stir up inside "Spider-Man's" body. Doc Ock can't handle it and is humbled as he's hit with all of the death, loss and "power and responsibility" stuff Peter has faced. Ock does a face turn and suddenly realizes what it means to be Spider-Man.
Peter then dies in Doc Ock's body, as "Spider-Man" promises to carry on in his name. With all of Peter's memories and his "advanced intellect", Ock promises to be a "Superior Spider-Man".
So there's the new Spider-Man: Otto Octavius inside Peter Parker's body with all of his memories. That's...completely unexpected. Kinda' tough to have the new version of your hero revolve around a brain swap. Also tough to have to root for Doc Ock, who's pretty much been portrayed as a scumbag.
I see several ways how they could bring back Peter, though. They could write that the Doc Ock thing simply wears out after awhile and the real Peter comes back to the surface. He was there all along. Or, that Ock had some sort of back-up "Octobot" of Peter's consciousness, which zaps itself into Spider-Man's body at some point. Heck, even have the Jackal bring back a clone and mess with that. Since the brain swap involved a lot of science-y stuff, all ya' gotta' do is whip up some techno-babble stuff and things are back to normal. There wold just be a lot of damage control as Marvel wold insist: "Peter was there, all along".
Frankly, it feels very random to me. I don't get why they suddenly decided to "kill" Peter Parker. He's "died" before ("The Other"), so it's no big deal. Honestly, if something like this would've happened in the 70's or even 80's, it would've just been in-line with the main title and not a "NEW #1" or anything. "The Brain Swap Saga" it would've been known as. Yet now they'll always have a "Doc Spidey Era" in Spider-Man's timeline. Whether it sits next to Ben Reilly and Mephisto remains to be seen.
The hardest thing to get around is the fact that The Villain Won and basically raped the hero. Doc Ock was dying, but then hopped into Peter Parker's body, let him die and took over as Spider-Man. Even getting down to some heavy petting with Mary Jane. They can throw in all this stuff about Peter's memories making Ock "heroic", but it's a very hard sell. But...Marvel will still make money off of it, albeit temporarily.
I don't feel ripped-off or anything. Even though I got back into Spidey around 2007, my interest has kinda' waned since then. I'll still pick him up, occasionally, but it hasn't had that "MUST READ/Can't Wait for Next Month" vibe for me.