I saw flashes of potential with Chung in 2010 and 2011. He played great in the SB vs the Giants. I think his 2012 season was pretty bad though considering he got benched. I didn't watch many Eagles games and when I did he didn't really stand out.
My take on this move is that BB sees SOME potential in Chung and wants to see if he ll do better as the SS in the single high safety coverage. He would play to his strengths because I remember Chung being a pretty good run defender and better at playing in the box.
Another thought that I had on this signing was that BB saw our draft needs/draft board and realized he wasn't gonna be able to take a highly regarded safety because of our more pressing needs at OL, DL, LB, and TE. Might as well bring back Chung on little money and give him a shot to beat out Harmon/Wilson/Wilson for SS role.