Quick idea off the top of my head - Orton feuds with Sheamus after he successfully retains against Del Rio at NOC. Orton turns heel in the feud and by the end of it, Orton wins the WHC. He keeps it until Wrestlemania. Before then, Ziggler turns face. I happen to think he is a better heel, but he is already getting cheers and dumping Vicke could probably easily make him a complete face. Leading up to Wrestlemania, Ziggler challenges Orton at Wrestlemania and says he prepares to he cash in MITB there, and so he does - defeating Orton one-on-one for the belt. Either way, I think it would be fitting for Ziggler to win the belt at WM, or at least walk out as champion, even if he walks in as champ in some way, and whp else for him to fight other than Orton? Sheamus? Del Rio? Fighting a new main eventer wouldn't work.