#3 Roman Reigns turns heel
Roman Reigns may be getting cheered now but it's only a matter of time before the audience turns on him once more. The best way to keep a character like him fresh could be to turn him heel again.
Dean Ambrose's heel turn was fresh and intense until poor booking got in the way of good programming. Seth Rollins seems to have gotten a fresh coat of paint on his character since turning heel as well and Roman Reigns could only benefit by working with young babyfaces and elevating them on SmackDown.
I wouldn't necessarily be opposed to a program between Roman Reigns and Shorty G, where Shorty G is elevated to the very top, just like what happened in his program with King Corbin. Another person who could certainly take over the top babyface spot from Roman Reigns is John Morrison, who is scheduled to come in anytime now.
Roman Reigns has been a babyface for most of his 'main roster' career and it may be time for a change at last. WWE waited far too long with John Cena but they really cannot afford to do the same with The Big Dog.