Gotta hand it to Stephen. Guy really cares about Professional Wrestling. Not saying that you can't enjoy the product and interact with it, but he really seems to enjoy embedding himself into the culture.
As for Punk I think this is a better outlet than him wrestling. He always has a creative mind, and sometimes that bleeds over into other things. Rock oozes charisma and was always going to make in Hollywood. Jericho despite his recent character flaws, doesn't shy away from the fact that he loves to perform and make music.
MMA really wasn't for Punk, but something that could tap into his ability to draw a reaction. He will probably do well with this.