Various rumor mills have suggested that the finish is still very much up in the air. Whereas the other main events, like Triple H vs Undertaker and CM Punk vs Chris Jericho are extremely predictable, you could make a legitimate case for either Rock or Cena coming out on top.
Conversely, there are good reasons for both of them not to go over in this match.
You cannot have outside interference in this match. Forget about any plans for Miz, Vince McMahon, John Laurinaitis or anyone else doing a run-in. One superstar must decisively defeat the other on his own.
However, a decisive outcome is different from one that is perfectly clean. I have had a lot of fun writing up the following scenario for WrestleMania 28.
I see a fast and furious contest with the Miami crowd entirely behind The Rock—Cena cannot even get a 50-50 crowd split in his hometown of Boston. I would be shocked if Cena got more than 10 percent of the crowd on his side.
The Sun Life Stadium crowd will be rabid for The Great One. I could honestly see the reaction being close to ECW: One Night Stand level, minus some of the more colorful chants at Cena.
The Rock will kick out of an Attitude Adjustment and Cena will kick out of a Rock Bottom, both somewhere around the 10 to 15-minute mark. There is no way that this match will end on the first finisher.
After that, Rock and Cena will torture each other with the Sharpshooter and STF respectively, though it would be interesting if they used each others submission holds at one point.
Look for Cena to power out of the Sharpshooter and nail the "five moves of doom" on the People's Champ. Just as Cena goes for the Five-Knuckle Shuffle, Rock kips up and nails a second Rock Bottom. The Miami crowd goes absolutely nuts as the elbow pad comes off and the Great One bounces off the ropes.
Can Cena dodge the People's Elbow? Nope, The Rock hits it. One...two...and to the shock of the Miami crowd, Cena kicks out.
A stunned Rock rolls out of the ring and gets a steel chair. The referee obstructs his path to Cena and tries to take the foreign object away from the Great One. Cena quickly gets up and surprises Rock with another Attitude Adjustment.
One...two...Rock kicks out! Cena sits up in disbelief and gets to his feet. He tries to lock in the STF, but Rock rolls on his back and kicks Cena into the referee.
Rock is shaking off the cobwebs as Cena looks at the chair that his opponent brought into the ring. He picks it up and thinks about it for a moment. Cena puts on the old "angry face" and drops the chair while shaking his head.
"That's not how we're gonna end this Miami. This fruity pebble don't need a chair," Cena says to the crowd. Rock gets to his feet. He lifts The Rock, hoists him onto his shoulders and looks at the crowd. Cena smiles and says "Rise above the hate," before delivering the Attitude Adjustment.
But Rock manages to land on his feet. He kicks Cena right in the crotch and quickly grabs the steel chair. Rock doesn't hesitate for even a second and slams it right across Cena's head. He throws the chair out of the ring and rips off his second elbow pad. He bounces once, twice and lands another People's Elbow.
The referee crawls back to the center of the ring as Rock makes the cover.
One...two...three. The Rock wins. He celebrates in the middle of the ring as confetti falls. The final shot of WrestleMania 28 is Cena on the outside of the ring, staring in shock.
Raw opens the next night with footage of a dejected Cena leaving Sun Life Stadium the previous night, having refused to give an interview or say a word to anyone. The Rock comes out to a thunderous ovation. He says what an honor it has been to come back to the WWE and to finally end the fruity pebble's reign at the top.
He reiterates that when he said he was never leaving, he meant it, and promises to come back to entertain the fans.
"If ya smellllllllllllllll..." "Awesome! I came to play..."
Miz comes out and applauds sarcastically. He congratulates Rock on his victory the previous night, but insists that Rock only faced Cena because he was afraid to go "one on one, with the awesome one." After all, Miz defeated Cena at last year's WrestleMania too, so shouldn't The Rock have faced Miz the night before?
Miz challenges The Rock to a match at WrestleMania 29. Just as The Rock looks ready to accept, Laurinaitis comes out and brags about being made general manager of both shows. He says that his first act as permanent general manager of both Raw and SmackDown is to book The Rock and Miz for later that night.
Throughout the night, we get dueling interviews and segments with Rock and Miz. There is no sign of Cena anywhere. We see Zack Ryder trying to contact his old friend on the phone, but he has to settle for leaving a message congratulating him on a great effort.
Finally, at the end of the night, Miz and Rock both come out for the main event. The bell rings and they begin to circle one another. They tie up and The Rock shoves Miz to the mat. Miz rolls out of the ring muttering to himself furiously.
Rock tells Miz to get back in the ring and just bring it. Suddenly, Cena slams him in the back with a steel chair. An almost deranged looking Cena hits Rock repeatedly and dares Miz to come into the ring.
The Awesome One hightails it up the ramp and leaves Rock alone and defenseless. Cena absolutely beats the hell out of The Rock and ends the night with an Attitude Adjustment through the announcer's table. He gets on the mic as if he's about to speak, but simply walks away.
From there, the WWE could go a lot of routes. They could turn Cena full heel, or just leave him as a face with a much greater edge. Either way, the John Cena character has to change after WrestleMania 28.
Given Rock's commitment to the WWE, Cena can win a rematch at SummerSlam or Survivor Series. I see Cena fighting Undertaker at WrestleMania 29 for one of the major titles, it's too big a match not to have. Rock can fight CM Punk or the Miz at WrestleMania 29.
The point of the finish is to emphasize the differences between the two characters and the two eras. John Cena could have won the match by using a steel chair, which Rock himself brought into the ring. He thought he would "rise above the hate" and do things his way.
The Rock, a product of the Attitude Era, has no reservations about using a steel chair. It doesn't matter that The Rock is the biggest face of all time—he came back to beat Cena, period. As long as he ends it with a People's Elbow and a one-two-three count, the fans in Miami will go crazy.
Cena on the other hand, does not come out of the match looking weak. He did what he thought was right and got burned for it. That makes him much easier to relate to in the eyes of adult fans, and still pure in the eyes of his young fans.
A typical superman win by Cena would be outright unacceptable in the eyes of the Miami fans in attendance. Turning Cena heel during the match and having him win through outside interference would just be a rehash of WrestleMania 17. Rock really has to win the match and I believe the finish described above (or something similar) can make everyone happy.