Cena retaining is a forgone conclusion. The match at Hell In A Cell was harmless, but they can't rely on that feel good moment of Cena winning the gold after recovering from an injury again. Sandow failed in his attempt to cash-in, and WWE taking the WHC off of Cena after his triumphant return wouldn't make any sense. It's John Cena, but still, he needs more time as champion to reestablish the WHC as a prestigious main event world title.
The bigger question is, what's next for Del Rio after Survivor Series? He's spent a good hunk of 2013 in the WHC picture, but after two consecutive loses to Cena, I can't picture a scenario, where WWE reinserts Del Rio into the WHC picture as a legit challenger. The WWE Championship picture is out of the question, because there's no room for Del Rio in the corporate takeover storyline, and a heel Randy Orton is WWE Champion.
To be honest, I think Del Rio needs some time away from ANY world title pictures in WWE. Del Rio being world champion and chasing world titles is beyond the tiresome and exhausted point now, and I don't know about anyone else, but I'm beyond burnt out on Del Rio clogging up the WHC scene as a champion and challenger.