Out of everything on the list this one is the most likely. Watch CM Punk's matches and you'll see a unique blend of old school wrestling and muay thai kick boxing, add that the to Jiu-Jitsu training he's received from martial arts legend Rener Gracie and it appears Punk is well placed to become a professional martial artist or fighter. Rumours have been circulating that Punk could join MMA organisations such as UFC even when he was still in WWE, he was even challenged recently by Green Power Ranger Jason David Frank, and we all know Punk likes to fight. It's also no secret that he's an MMA fan, appearing regularly at UFC events and broadcasts, and he's even struck up a friendship with UFC president Dana White. Punk has some level of interest in competing and Gracie believes that despite his age Punk could be reasonably successful. He's obviously a great athlete and is extremely driven, the tools are there, but it remains to be seen whether or not he decides to take that next step and follow the likes of Brock Lesnar and Batista into the octagon.