After months (and months) of studiously avoiding the issue of exactly what the frell happened at the end of "One More Day," some info has finally started to trickle out.
First, in the freebie Marvel: Your Universe Saga (available free this week at Marvel Digital Comics, if your missed it at your local shop), which recaps the last few years of Marvel continuity, we get this gem:
Using his vast powers, Mephisto saved Aunt May's life--at the cost of Peter and Mary Jane's marriage, which the demon erased from history. Unaware of what he has lost, Spider-Man continues his adventures.Now, one would hope Marvel wouldn't print that without it being kind of official. So it wasn't some amnesia spell--Mephisto actually rewrote history, and Peter Parker is unaware of it.
Which is interestingwhen we consider the other precept they laid down back in the first issue of Brand New Day: ""Absolutely no one knows that Peter Parker is Spider-Man. Not Daredevil, not the Avengers, not anyone." At the time, I wondered exactly how that would play out with characters who HAD to know Spidey's identity, such as Venom or Norman Osborn (unless gazillions of stories were wipe out of continuity). This made the situation sound more like a mind-wipe than an actual historical change. But now Marvel says nope, it's a historical change.
Which brings us to Amazing Spider-Man #569, where Norman Osborn is confronting Peter Parker (click to make it larger if you can't read it):
Second thing to note: Venom can sense old host Eddie Brock from blocks away, but can't sense that Parker was a former host when they're in the same room. And he remembers that he was bonded with Spider-Man, but not Parker.
Third thing, when Spider-Man confronts Osborn:
So, assuming everyone's been playing fair with us, (including the editorial staff in their "official" pronouncements):
Peter doesn't know about the deal with Mephisto, which actually altered the timeline (so this speculation would be wrong).
Osborn used to know who Spider-Man was, but doesn't anymore (so past stories DID happen, Peter remembers, others don't, at least not the revealing parts).
Everything "we" did is still "up and running." (so the reason for the lack of memories is due to some specific steps Peter and ? took)
So Mephisto changed history, but within that new history, Peter and someone did something to erase memories of Spider-Man's secret ID.
Who? Could be Professor X...he's got the mojo to wipe out that many memories. But a Spider-Man connection? And could he effect an alien symbiote like Venom?
Could be Doctor Strange. He's got the mojo, at least from time to time. And he was hangin' with Webhead, during the "New Avengers on the run" days.
But what about the Sentry? He's pulled this "everybody forget about me" shtick twice now, with his awesomely undefined powers and his ultra-super-computer CLOC (and with help from Dr. Strange the second time). He and Spidey were New Avengers together, and Avengers HQ was the Sentry's Watchtower.
So what if, after Peter reveals his identity publicly (but before he splits the official Avengers), he has second thoughts, and gets Sentry to help him undo that with his awesome memory-eras-o-vision thingie? Or, after he splits, he sneaks back in, and gets the Sentry to help him anyway (or someone else..."we"...Doc Strange, perhaps?).
Just noodling. But that's my guess: Sentry.
Now the real question. Was that part of the deal with Mephisto...perhaps what Mary Jane whispered to him? Or was it just a natural occurrence of the new timeline--without MJ's support he wasn't as confident of his decision to reveal his identity, so he recanted and rigged up a giant Zatanna for everyone?
Obviously, I think about these things too much...