According to his twitter account, Derrick Williams (@DWheelz12), the former Penn State WR will sign with the Steelers. He will be added to the offseason roster under a reserve/futures contract. He was originally drafted by the Detroit Lions with the 18th pick of the 3rd round in 2009.
At the NFL combine he ran a 4.55 in the 40 yd. dash; slower than what he was expected to run because he was ill at the time.
The Lions released him in September of this past season and the Steelers will pick him up and give him a shot at a roster spot for 2012.
Other recent Reserve contract signings by the Steelers: Antonio Smith (CB) out of Bowling Green, and Jimmy Young (WR) out of TCU.