I would put him on your league's trade block and see what offers come your way. You can get more than Ridley for him (Gore, AP, MJD?). I would target RB's that are not in a time-share program with another RB.
Not sure what to tell you, I myself have been wondering whether to give up MJD for him (in a package deal of course)...depends on whose biting in your league. If anything, he should have a monster game this week which should put his stock even higher. If you end up keeping him, see if you can buy low on F. Jackson.
In a redraft, I'm holding on to him unless I get a clear non-timeshare stud RB back. There's absolutely no way he takes second fiddle to FJax ever again.
Then again, I exclusively play in keeper leagues. I've got him for $11 in my auction league next year (2 QB league, and I'd be tempted to deal him for Cam Newton, who can be kept for $17 next year), and as a 4th rounder in my snake league next year. w00t w00t.
No way I'd trade him Ridley! No way! I wouldn't take any less than 2 top tier talents at their positions. If there are no takers, I hold on to him because the guy is a freak. He won't hurt you because the Bills are insane if they don't grant him the bulk of the load when Jackson gets back. Jack is over 30. It's Spiller's time now in Buffalo.