I'm gonna focus on the WWE World Heavyweight Title only. I'm guessing Cena will be United States Champion for the next 6-7 months.. perhaps, until WrestleMania 32 where a Challenger finally defeats him. As for Daniel Bryan and the Intercontinental Championship, I can see him holding it until Neville wins it from him or something.
Extreme Rules: Seth Rollins defeats Randy Orton in a Steel Cage match by escaping the cage while Orton deals with J&J security.
Payback: Roman Reigns defeats Seth Rollins by disqualification. Therefore, still your WWE World Heavyweight Champion, Seth Rollins!
Money In The Bank: Seth Rollins defeats Ryback.
Battleground: Seth Rollins defeats Dolph Ziggler to retain his WWE World Heavyweight Championship. Dolph Ziggler earns this title shot by defeating Rollins on RAW but Rollins defeats him clean at the PPV to somehow look strong as the Champion instead of the typical coward heel wins by DQ, count-out or escaping the cage.
SummerSlam: Seth Rollins defeats Brock Lesnar due to Paul Heyman costing his client the match, align himself with Seth Rollins.
The projected future to WrestleMania 32 should be leading to a Dean Ambrose vs. Seth Rollins vs. Roman Reigns triple threat Shield match that we've been so desperately waiting. That would probably be the time where it would be fitting for Roman Reigns to win the Title and his family can be happy...