As it stands today, I would take Brad Johnson over Favre any day of the week and twice on Sunday. Favre's decision making is atrocious, and he no longer has the physical talent to overcome the stupid decisions he makes. He should have hung 'em up.
As for history, it will look very kindly on Brett. No-brainer, first ballot Hall of Fame. I wouldn't put him in a class with Bradshaw, Montana, Elway, Aikman....but he's in that group right behind (Steve Young, Roger Staubach, and the like....). Fire away, Packer rubes.