Its great he's a company man and all, but I think Cena comes off as a little too dedicated to pro wrestling. Does the guy even have a personal life to speak of? When Kurt Angle has to tell you to slow down because you're wearing yourself out, you know you've got problems.
Guys like Ric Flair and Chris Benoit, are good examples of why you should never build your life around pro wrestling. I'd love to hear of John demanding time off or at least doing something selfish that indicates he's putting his own well being ahead of WWE.
Reminds me of the article Paul Heyman wrote about Cena a few months ago. Cena has no wife nor children. While other guys hate being awakened at weird hours of the night to give interviews over the phone, Cena welcomes it. Vince was certainly right when he said that Cena will be money as long as he doesn't have any problems (drugs, personal, etc.) when Paul pushed to debut him on Smackdown.
I still have a feeling though that Cena is going to burn out in a few years and take a break from the business just like Big Show and Jericho did. No one can keep up the kind of schedule he's doing for that long.