If Fred Jackson retired today, he would not be a Hall of Fame candidate. However, what if he lasted another 3-5 years at the same level of production that he was on pace for last season? It might sound like a long shot, but the induction of Curtis Martin gives some credence to the possibility.
The career similarities of Jackson and Martin are stunning. Curtis Martin was the oldest player to win a rushing title when he did so in 2004. He was 31 years old, the same age that Fred Jackson is going to be this season, and he should be able to challenge for a rushing title if given enough touches next year. Jackson and Martin also have similar statistics when it comes to catching the ball out the backfield (Martin had 10 TD receptions in 11 seasons, Jackson has 4 in 5 seasons.)
A big reason why Jackson should be given consideration for the Hall of Fame is that Jackson has a much higher YPA average than Martin. Martin averaged 4.0 ypc in his career while Jackson has 4.6 ypc in his career. All of this comes in an era where the Bills have had absolutely nothing in terms of talent at the O-line spot. Give Fred the luxury of 300+ carries in a season and his rushing numbers would be much better than Martin's.
Fred Jackson needs to keep it up for 3-5 more seasons before any of this is more than speculation. However, if he does maintain this level of production, he should get a serious look from the Hall.