The funny thing is that I'm prepared to wager that OMD is, in fact, almost the opposite of what it appears: it's one of those stories that's designed to prove that their love was always meant to be, and not even magic (in the person of Mephisto, evidently) can sunder it.
If I have this right, the Big M gives Pete the choice: May can live, but all memory of his marriage to MJ, and their life together, will be erased. I might point out, by the way, that The Watcher accomplished virtually the same thing in one panel in last week's FF #550, and no one even batted an eye. Pete takes him up on it (since this way no one dies), and we get 9 months to a year of "old-school" Spidey stories.
Except... there's this redhead he keeps running into. And there's just something about her... and we'll eventually be back at status quo, with memories restored. Presumably, at that point, she'll drop the "Jackpot" identity, though who knows?
I think there's plenty of clues that this is the case, but the most compelling for me is that they're not removing MJ from the Marvel U-- what's the point of keeping her around if not for an eventual reunion? And I would be VERY surprised if Marvel scooped up Terry Moore to write the "Spider-Man Loves Mary Jane" series if the future of that relationship were about to be wiped out altogether.
Plus, of course, there's the report from last summer's cons that Quesada, responding to an annoyed fan, blurted out "Well, it's not permanent," before catching himself.
And while it all sounds dumb to me, if it gets me Dan Slott Spidey on a regular basis, I have no complaints. Well, not many.