Bell won a superbowl last year as third back for the Saints. He actually posted some decent numbers last year with 654 yards and 5 TDs and despite being third on the depth chart actually led the team in carries. He's 27 and has good size at 6 ft, 220lbs. Bell came into the league as undrafted free agent and had a promising rookie year in Denver, but barely played in the next few years until he enjoyed a resurgence with the Saints last year. He was rarely used in the passing game in New Orleans with Reggie Bush and Pierre Thomas being more obvious options, but he did show some pass catching ability in Denver.
If the Eagles are in the market for a backup veteran RB, Bell would seem to fit that role well. Bell is technically a restricted free agent, but he was tendered at the lowest possible level. Since he was an undrafted free agent, New Orleans would have a chance to match any offer but if they didn't the team he signs with would not have to surrender any picks.