This is an interesting group to project because you of the ageless wonder, a young buc with only one season of NFL data, a highly regarded QB who recently changed teams, and the hottest QB on fantasy draft boards. So without further ado:
Aaron Rodgers may be the QB that all of your fantasy friends are talking about (and his 4500+ yards earn him this status), he will not be throwing the most TDs of this group. Cutler will likely toss a few more TDs, though he will also toss nearly 3 times as many interceptions and 900 fewer yards. The difference is that Cutler has and is projected to keep higher rates of TD and interception throws than Rodgers.
Favre meanwhile will continue to put up decent numbers joining, for the second time, the very exclusive club of 40 year old QBs throwing for 3000 or more yards. He will join himself, Warren Moon and Vinny Testeverde. The major change in Favre's performance is likely to be in his interception rate. He threw less than two interceptions for every 100 attempts last season. His career average has him throwing over 3 interceptions for every 100 attempts. Combine his own historical performance with his advanced age, I see his interception total going up from 7 last year to 18 this year.