O.J. started eight games last year for the Redskins having played in 13 games with three interceptions. Given OJ's injury history, is it surprising they signed him, but he is a quality veteran that has a wealth of knowledge on the game.
Right now the Eagles depth chart looks like this (years experience in parenthesis)
OJ likely got a minimum contract and is not a lock to make the team. His veteran instincts should help the safeties in training camp. That's the only thing I can think of. The Eagles defense allowed the 9th most passing yards against.
Let's all root for OJ to make the team for RGIII's sake.