I need to watch it again but it looked like Cena was the heel in theexchange. It looked to me like he made his move first and Ryback nailed him.

I doubt they'd end the show with a 'Feed Me More' chant if Ryback was the intended heel, especially after bringing him out to beat the breaks off Henry. The crowd chants "Finish It!" with Ryback.

Add that to Cena's recent behavior, and it adds up to Cena being the heel IMO.

Yes, I realize their track record the last 5-6 years suggests it would be Ryback going heel and backfiring, but it just didn't come across that way to me.