According to several WWE sources, there was a lot of tension and turmoil going into Sunday night's WWE Survivor Series pay-per-view. The original plan for the past few weeks was for CM Punk to retain the WWE title until the Royal Rumble pay-per-view. The Rock would win it there and carry it into WrestleMania 29. Vince McMahon was high on this idea as well. Others in the company wanted Punk to drop the title at Survivor Series. In the end, they went with Vince's idea (surprised?!) of CM Punk retaining the title as you all saw Sunday night.
Several people within the company were worried about not protecting Ryback enough but one of Ryback’s biggest supporters, Vince McMahon, was in favor of Punk keeping the title as we noted. The Seth Rollins/Dean Ambrose/Roman Reigns main roster call-ups was a way to "protect" Ryback. More on this later today.
As of last week, the plan was to do a Survivor Series rematch (Ryback vs. Cena vs. Punk) at WWE's TLC pay-per-view. Of course, plans can and always do change.
No matter what happens, The Rock is expected to win the title and go into WrestleMania 29 as WWE Champion. Obviously, he'd lose it there or at RAW the following night as he'll be leaving again.