It looks like McFadden has decided to stay in Oakland for one more season.
I think the Bengals not pursuing McFadden is the right move. The success of running backs in the NFL is realatively short lived and McFadden has not been the most durable back lately. Bringing him in would be a gamble that he would only be active in half the games in a season and for on offense looking to lean on the run, that is not good business.
Don't expect the Bengals to make their free agency mark with a running back. There are options on the roster and a few more in the draft.
UPDATE: Adam Schefter of ESPN reports that the one-year deal between McFadden and the Raiders is for $4 million.
(Anthony Cosenza contributed to this report.)