Or at least Machinima is claiming that it's Sean. Looking at the trailer I wouldn't have guessed it's Sean up until that last clip that looks like it was taken from Street Fighter III: 3rd Strike. Others are guessing it's Rolento. You know, that guy with the barret and stick?
I'm sticking with Sean because who else brings a colored basketball around in Street Fighter? Can't wait for a full on character reveal trailer.