Re: Cena 36 - who's next to carry the company?
I'm not sure if we'll see another "Cena" emerge in the next couple of years. I don't know if there's anyone on the current roster that can fill that spot. As much as the WWE would love it, Sheamus doesn't have the ability to fully replace someone as versatile as John Cena. He's not as strong in the ring, or on the mic, he doesn't have as much charisma, or marketability. The same could probably be said for Ryback, who I believe might be even less versatile than Sheamus.
What I think we'll get is a collection of superstars who are just below that level (in some cases, quite far below that level). Sheamus, Ryback, Punk, Orton, Bryan, Sandow, Ambrose, Cesaro, Miz, etc. I think that the WWE are making a coinsice effort to strengthen the entire roster, after spending a long period of time solely relying on John Cena - and it's about damn time.
After Cena leaves, we're looking at the new New Generation. A time where there isn't necessarily one "main" guy, but a selection of top-tier talent.