I think there is way too many factors and how many TDs would just be a random guess.
I'm more interested in who the returners will be.
Clearly Cobb and Monty are thought to be options but early in the year it seems like Mike McCarthy always bans important role players from being returners.
I believe I read a story about WR Cobb, CB Rollins, RB Jones and RB Mays all practicing as a punt returner, but it's early now and based on past years the Packers seem to like to rotate guys and and out of this... so guys that haven't been doing it might get chances later.
I would like to see WR Davis get more shots as a returner, because if he can learn to protect the ball a bit better, then he could become a darn good returner. Also maybe Janis on kick returns.