Followed Cobbs at UNT, and he was a great back in College. Since I went to UNT I also paid attention when he went to the Pats. Eventhough he was a great D1 RB you never know how well they will do in the pros. I followed each and every game he played, and from what he showed in New England he will be a good risk for any team. He was their top back in pre season. And below is some NFL pre season stats:
(number 7 in Rushin yards)
(number 2 in TDs)
The reason the traded him is that they are loaded at RB, and knew that because he did so well in preseason someone would pick him up if they put him on the PS. They did the only thing they could and traded him.
Since most Steelers fans are not going to know who this kid is unless they are big into College Football, a good sign that this was a good move is by looking at the how disappointed the NE fans are that they lost him. They saw him every game.