I'm fairly certain Orton won't win the championship. Reigns will likely take him out during the ladder match before being screwed by Triple H and/or Rollins right when he's on the cusp of pulling down the title(s.) Then it would make the most sense for Reigns to go over him one-on-one at Battleground as a way to set up the match between he and Triple H at Summerslam (a sort of "You beat the protege, now let's see if you can beat the master" type of deal.)
I'm still hoping Wyatt gets the title to set up a feud with Daniel Bryan at Summerslam and beyond (I feel those two could fight it out all the way to the cell at HIAC in October), granted that Bryan is able to return by then.
Who could you honestly see cashing in, though? Rollins is the only person to plausibly do so, and I don't see them hotshotting the title onto him this quickly. Besides, the fact that Cole and JBL mentioned on Raw the possibility of a cash-in happening at the PPV makes me believe the chances of it occurring are actually pretty low now. Probably what will happen at the very most is Rollins trying to cash in on Cena but Ambrose runs out and stops him by initiating a brawl with him to the back or through the crowd or something.