While the cash must seem nice, he's also got to keep in mind that his body may not be able to take too many of those nasty hits he keep taking. With all the money he's already made, I think he should walk away while he still can walk, and not end up with lifelong issues like limps etc.
yes, it's very likely the right decision for his health, but he can make whatever decision he wants to make. It's sad to see a season like last season, because when he's on (like his MVP-caliber season prior to last season), he is awesome to watch.
The NFL makes far more drama out of this than does Favre. Thing is, as soon as he takes more than those regular ~6 months off, his body will tell him to quit, I think. He hasn't let it catch up in some 30 years.