This is another one of my out-there predictions for Survivor Series, along with the potential of a screwjob (and don't discount that one completely, they will be in Cena's hometown!).
A lot of people are speculating that they're holding off the Edge return to see if Christian will be jumping to WWE, but I think we could see him return this weekend. Obviously it would be during the Big Show/Undertaker casket match (a match synonymous with copious amounts of run-ins).
But would it be to get revenge on Undertaker? The last we saw Edge, he was "sent to hell" by Taker after their Hell in a Cell match at SummerSlam. That's where I think things get interesting. Yeah, the whole idea of him going through the ring and the flames shooting up is a bit silly (but who doesn't long for the old days of Ultimate Warrior puking after getting cursed by Papa Shango?), but I'm hoping they don't just forget about that detail when he comes back.
So sure, he could come back for revenge on Undertaker. Maybe Edge didn't like his visit to hell. But what if his trip to hell has brought Edge over to Undertaker's "dark side"? If they went with it like that, he could appear during the match on Sunday (and the crowd will go nuts, thinking he's about to cost Undertaker the match) and help Undertaker put Big Show in the casket.. and light it on fire.
Now, I'm not suggesting that there will be tag team matches with Edge/Taker taking on all-comers, or some type of new stable (Ministry meets The Brood). But they could turn Edge into someone the fans want to get behind, while still keeping his character as dark and crazy as he was before he left.