I think Bryan or Punk will take the title from him at Wrestlemania. Orton is more intriguing than he has been in quite some time but that isn't saying much. He's still boring and their attempt to recreate a Corporation angle with Orton being the Rock or Triple H isn't going to have staying power with fans.
He just doesn't have the charisma or mic skills to transcend the sport for a period of time and that's been evident of his previous title runs. I get he's the top heel but I don't see him having a Punk esque title run. I could be completely wrong though. If they go ahead with this Reigns push or Sheamus comes back and fights for the title after Bryan fails to go over, it could be possible that he is champion till Summerslam or so.