It appears Peyton has been going through some throwing exercises at Duke University under the guidance of his former offensive coordinator and current Duke head coach, David Cutcliffe. It's tough to tell, but the video above shows Manning "going through an aggressive throwing session in his Colts helmet, shoulder pads and jersey."
It certainly does look like the man throwing is wearing a number 18 jersey. And the happy feet, oh the happy feet. For those unpersuaded by the dancing feet, Albert Breer of the NFL Network says a source confirmed it was Manning.
Anyway, Peyton can still throw a football to another person. So, New York Jets Super Bowl XLVII or bust.