According to the Football Outsiders Almanac 2009, Jones "displayed all the mobility of the Roebling Bridge" last season, so this isn't a move to get excited about.
Wear-and-tear might have finally caught up to him, but Cincy Jungle says "Jones has been a shell for the past two seasons, in our opinion, and it was only a matter of time before he was replaced." It might have been injuries that led his release, but the Bengals blamed injuries for the release of former Pro Bowl RT Willie Anderson before the 2008 season, but he seemed healthy and started 11 games for Baltimore in 2008. The Bengals might have released Jones just to save money.
The big problem with signing him is that someone has to go to make room for Jones, and he's probably looking to get paid like he's a starting left tackle. Maybe in the range of $4 million (pro-rated) for the season. Greg Bedard said:
Should Clifton be injured further, the Packers might consider signing Jones.
That seems possible. If LT Chad Clifton re-injures his ankle, and has to be placed on I.R., they would have the roster spot available. And they certainly would have a need for a backup, or starting, left tackle. After Clifton and LT Daryn Colledge, the only other player who played a lot at LT in the preseason was Jamon Meredith, and he was just signed off the practice squad by Buffalo.