He should use a high flying move once in a while,and then people will forget his flaws and everyone will mark out for him once in a while. It has worked for Angle (moonsault), Lesnar(Shooting Star press) and Steiner (frankensteiner). Of course they also usually miss and sometimes look like they are going to kill themselves in the process, but I'm not a huge fan of Cena's anyway so its a risk that I'm willing to take.