I did. Cena is the undisputed #1 guy of the current era, just as you said. If Rock puts him over, nothing will really happen. He'll still be the undisputed top guy, Cena fans will still love the guy, and Cena haters will still think Rock > Cena. Cena will come back the next night on top, as the unbeatable Superman, as the fans still boo like crazy. Nothing changes, nothing happens, and one of the biggest matches in WWE history didn't accomplish a thing.
We discuss this in the TNA thread all the time. When pushing a face gets rejected, you let him take a few losses in a way that builds sympathy towards the character. One of you (I think it was Hoss) posted earlier that they are discussing more than one Rock/Cena. So a clean win for the Rock, which sets up Cena being a legitimate underdog going into Rock/Cena II (hopefully at Summerslam) would do much more for Cena than Cena simply winning here.
Which probably means Cena will go over.