F4WOnline.com is reporting the current plan is for John Cena to tie Ric Flair's record of 16 world title reigns, but that won't happen until next year. WWE wants Roman Reigns to get a WWE World Heavyweight Championship run before dropping the belt to Cena, which would happen sometime in 2016.
So while that report answers some questions, it obviously raises a slew of others.
This doesn't rule out that Sting could get a short run with the World Heavyweight Championship, but it could be the first concrete signs that WWE might be building to Reigns vs. Rollins as the championship match at WrestleMania next year. If Rollins doesn't drop the title before WrestleMania 32, that would give him essentially a one-year title reign before dropping the title to his former Shield compatriot.
Rollins could also potentially lose the title to any number of challengers before WrestleMania rolls around, or lose the title for a short time and regain it. There's also the possibility that Rollins vs. Triple H at WrestleMania could be the end goal, but that would seem to leave a void of a top-tier heel for Reigns to take the title from.
All of this is purely speculation, of course, but it seems like we'll soon be getting a lot more of the beloved U.S. Open Challenge.