It's a bit more nuanced than that. Apparently, Otto Octavius (a.k.a. Doctor Octopus) was dying, so he engineered some scheme to switch brains with Peter Parker. Peter, in Doctor Octopus's body, dies, but somehow Doctor Octopus, in Peter's body, suddenly gains access to all of Peter's memories, showing that the brain transfer was not complete. Seeing Peter's whole life in that light, Doctor Octopus was inspired, and instead of using Spiderman's body for evil, he vows to not only fight crime, but to do a better job of it than Peter ever did, thus becoming the "superior" Spiderman.
Now, I'm not abundantly familiar with comics in general or Spiderman specifically, but I know that in comic books, few things are quite as temporary as the death of a superhero. This one example has a particularly easy retcon capability. After everyone gets tired of seeing Doctor Octopus trying to be Spiderman (which sounds like a pretty interesting story premise, actually), they could just say, "oh, Peter Parker's original memories and personality completely regenerated and deleted the Doctor Octopus persona from his brain," thus effectively returning Peter Parker to the role of Spider Man once again.
To tell you the truth, I was more offended by that one time they decided to let Spiderman be a black kid for a while. Like all such gimmickery, it was just a bizzarre plot twist to raise interest and sales, but this time they did it under the banner of racial equality. I found such a sentiment to be utterly false and pretensious. Of course they weren't going to let Spiderman be black forever. I knew, sure as anything, that before long Peter Parker would come back to life and we'd never hear from that black kid again. With that in mind, for them to suggest that they were being "progressive" or whatever came across as apallingly insincere. By the way, does anybody know how they retconned that? I remember hearing about it, but I never heard how they changed it back.
The idea sounds fine. The creepy parts with Aunt May and MJ are another issue. I was hoping for Otto to be well, in a stronger body, Peter to have his body, and them to go down in that kind of fight. Well, in this case 'brains' Ottos won to Spidey's bronze (powers).
Yeah, totally just having a random person be Peter was rude. I hoped Kenny Kong who could have worked out to gain more weight, maybe the spider power's gave him more IQ to surpass Peter or what not, would work rather than just some new character.
Why are you guys hating so much? OR COURSE Peter will be back. Does that mean we can't enjoy the story for itself? They've been setting up for this for a while now (like 100 issues since ock got sick?), and the writer seems genuinely enthusiastic about having a spider-man that people consider a menace again. The new status quo is kind of interesting. Enough that I might actually buy a few issues next time I'm at the shop. Just relax about it an enjoy the ride. There are more than two emotions in life. You don't need to be either ANGRY or CYNICAL. You're all like a bunch of winey kids complaining "are we there yet."