I'll want to see what was promised to Goodson in guarantees before I would definitely say what his role with the Jets will be, but a three year deal is an indication that this is not a "come to camp" deal.
I still believe that for now Bilal Powell will be the starter for this team since Powell is a versatile player: able to power run, good vision, decent out of the backfield, good pass blocker. He might not be All Day, but he's got no gaping holes in his game either. Powell might not excel in any one area, but he's solid at everything. More than anything, I see the move as an indictment of Joe McKnight's role with the offense and the backup could be relegated to special teams work exclusively as a result.
Cimini writes on ESPN NY that the Jets like Goodson a lot and thought he was a "sleeper" in this year's FA class.
Back in 2010, Goodson was able to show some of his abilities when he was with the Panthers. Goodson played behind DeAngelo Williams and when Williams was sidelined with injuries, Goodson worked with Jonathan Stewart and ended the 2010 season with 452 yards on 103 carries, or a 4.4 YPC average. Ball security was an issue though, where he put the ball on the turf four times (losing two) so the Jets staff will have to guard against that concern. Last year the Panthers traded him to the Raiders where he sat mostly behind Darren McFadden getting some mop up work, but averaging 6.3 YPC all the same.
I wouldn't put anything past the Jets, but I do think that this move to sign Goodson will lessen the Jets likelihood of drafting a running back in the first few rounds of the draft -- and that's why I want to see the guarantees that were given to Goodson first. If they didn't promise too much up front, then there's no reason to pass over a player they like a lot in the second or third round as long as the Goodson deal doesn't impact that. For now, the Jets have the power runner covered in Powell, and they've got the third down back covered in Goodson.