Cena's the man, by the way. The ****ing dude. I'm not even going into it again. The amount of talent he puts over is phenomenal. Punk got the longest reign since dopey times as champion when Cena was around. Daniel Bryan was made the top guy when Cena was around only for him to get banged up. He just played the role of 2 Cold Scorpio in a Shotgun Saturday Night jobber match with Brock Lesnar for **** sake.
The likes of Ziggler and Nexus were booked into oblivion long before Cena beat them clean.
But yes he does need to start getting phased out of the main event scene slightly. He'll always be involved in it when he is around but they need other alternatives. Bryan was one. Roman will be the next one. It'll be interesting to see how business goes with this change over the next year.