There has been a lot of speculation that Dwayne "The Rock" Johnson will be starring in the new Terminator 5 film. At this time, the reports are just rumors and have not been confirmed by Johnson or anyone associated with the film.
If chosen for the role, Terminator 5 is scheduled for a January 2014 production start. This would mean that if he was planning to return for WrestleMania XXX, his filming schedule would likely conflict with the January Royal Rumble PPV as well as the Elimination Chamber PPV in February.
The Rock has been praised for his work in helping to revitalize established franchises, such as Fast & Furious 6, G.I. Joe: Retaliation and Journey 2: The Mysterious Island.