According to an announcement by Dan Slott at the NYCC noted by a step-by-step accounting at the NYCC by CBR.
It noted that Dan Slott said:
Slott compared the tone to Gwen Stacy's death and "Kraven's Last Hunt." Then, "You want Spider-Man and Mary Jane back together? They're back together! But he's not Peter Parker."
This does not sit well with me, they have been together for a long time, he told Silver Sable (Hope she comes back soon), after turning her down, he wanted to be worthy of MJ and near the end of the Spider-Island arc MJ whispered "I love you" to Peter which he did not hear and granted he was wearing his costume at the time, She even bought a nightclub in his honor, so that they can celebrate his victor after Ends of the Earth. With these points, the fact that they do not end up together is wrong and should be reconsidered. I mean it looked to me like they were trying to make a go of things, and now they say they might not end up together, it just does not make sense.
What happens between now and issue 700 that changes their relationship this much.
For this reason I'm hoping this is more of Marvels teasing or even one of their twists where it is Peter but with a new identity, which was setup by technology or magic, in order to escape his identity being revealed by Doc Oc.