Does Cena have (visible) tattoos? If not, there's an angle he might fit well in....
Side note: I've been watching alot of the old ECW, and aside to some of the tag teams, and "new" guys (1997+), it seems like tattoos were TOTALLY not "in" for most of the big names. Even when they DID have them, they tended to be small, and almost not-noticable on TV.
Shane Douglas, Sabu, RVD, Taz, Sandman (Pre-barbedwire arm and face on arm tatoos, anyway), Dreamer, Chris Candido, Furnas and LaFond, Terry Funk, etc... I don't recall seeing any major inkage on any of them. Bam Bam Bigelow didn't really "Join" the company til mid-97. Raven had a couple on his shoulder, but that was about it.
OTOH, it seems like most of the tag teams were totally tatted up (Gangstas, Eliminators, Pitbulls).