I like the Rodgers comparison, and think that Cam has potential to be even better. Right now he's as old as Rodgers was when he first became a starter, and Cam is arguably having a better season. Give him a line, another decent receiver, and firm instructions to go through all his reads before he takes off, and he'll be one of the best in the league.
Not a popular thought on this board, but if you are looking at 2008 as what the team could do with both Stewart and Williams healthy, and if your boss is telling you that he wants the team built that way, and if both backs are still in prime years, then the moves makes a sort of sense.
If the team had ripped off another 12-4 season riding two starting caliber backs, no one would have said a word about the contracts. Simply put, he gambled and lost.