Trent Robinson is an interesting pick. He is a relatively small safety with good cover ability. I would say that, due to his cover ability, he is likely to plug in immediately as "starting" dime back. Additionally, he may be able to compete with Culliver for the nickle back position, though height (Robinson's lack thereof) may be an issue there?
I would also hazard a guess that Robinson might begin the season as the primary backup to both Goldson and Whitner. (Am I underestimating Spillman there? Thus far he has played only in goal line defense. My impression is that Splillman does not have very good cover ability and might be a liability as starting safety.) So that might imply a safety depth chart of: Whitner, Goldson, Robinson, Spillman, which still seems a little thin. (Who am I forgetting here?)
I would be interested to hear anyone's opinion regarding the secondary: corner as well, where presumably T Brown (rcb), Rogers and Culliver return as starting and nickle corners. Who do you see as 4, 5 and 6 at corner? Any chance Robinson gets the mix there as well, e.g., as backup to T Brown?