To get things started, I think it might be helpful to put what makes Statham The Great Statham he is in list form, and then decide if John Cena has what it takes to measure up. Here are the Elements of Statham, as I see them:

1) Abundance of muscles.
2) Refreshing self-awareness.
3) Ability to carry off comic relief effectively without making everyone uncomfortable.
4) Consistently convincing pretend-car-driving abilities.
5) Demonstrates impressive and innovative fighting styles.
6) Compelling in everything he's in, even when what he's in is Dungeon Siege.
7) Sexily European, yet also relatably working-man.
8) Bald.

I haven't seen Cena's previous fine film The Marine, because why would I? That thing was for wrestling fans only! But, as I was telling Zach and Angel today -- even though it was directed by Renny Harlin (uh oh!), the trailer for 12 Rounds makes me think this movie's going to melt my face off. It's certainly Statham-y in many ways, and that's just judging from the trailer: Cena screws over a psychopath (Crank! Transporter!), so said psychopath kidnaps Cena's girlfriend (Death Race-ish!) and requires him to do 12 impossible tasks (also Death Race-ish!) to pay off his debt and get her returned. He jumps from a busted-up town car onto a moving cable car, crashes a fire truck, jumps on a helicopter, jumps off a helicopter (Crank!), avoids dying in a crashing elevator, plays with guns, and saves the day. Not Statham specific, most of that, but the boy's got action chops. This cannot be denied. Let's run down the rest of the Elements of Statham and compare:

1) Abundance of muscles -- Obviously.
2) Refreshing self-awareness -- I have no idea, but I do know that he recorded a song called "Basic Thugonomics," which I think could clear this matter up. If he was serious with that, then he's not our guy and I hate him; if he was joking, he's the greatest.
3) Ability to carry off comic relief effectively without making everyone uncomfortable -- Based on his SNL appearance two weeks ago, I'm going to tentatively say that yes, he can. But that was a brief appearance, so I am need of more examples to make a final decision.
4) Consistently convincing pretend-car-driving abilities -- Yes. I believed he was crashing that firetruck, people.
5) Demonstrates impressive and innovative fighting styles -- He didn't do that in the trailer, but he is a famous wrestler, and as such has an entire list of hilariously named ("Spinebuster," "STF-U," "Five Knuckle Shuffle," etc.) "signature moves" on his Wikipedia page. At the very least, the man must know Judo, so I'm saying he meets this specification.
6) Compelling in everything he's in, even when what he's in is Dungeon Siege -- Hard to say. This is probably the most vital criterion, but until they write more roles for enormous grizzly bears with surprising versatility, The Rock has all of John Cena's potential crossover roles all to himself. Statham has millions of muscles, but at least he's a normal person-sized, which is a huge advantage John Cena does not enjoy.
7) Sexily European, yet also relatably working-man -- Cena's screwed on the sexy European part, but I'd say he's got the all-important blue collar rage down. James Bond he is not, but one out of two ain't bad.
8) Bald -- Unfortunately, he is not bald yet, but he's sporting a close enough cut. He should consider going the full Statham/Willis if he wants to be taken badass-ly though.

And in fairness, Cena hasn't had the advantage of working with scripts by Luc Besson, or that pair of lunatics Neveldine & Taylor, whose absurdity Statham has undoubtedly benefited from, so based on what I've seen, it's entirely possible that he could pull off some Statham-level antics if he had the chance. Let's just hope I don't want to throw 12 Rounds -- and John Cena with it -- in the trash compactor after I see it on Friday.