There's your WR depth we've been talking about since Holmes left.
A guy that seems to fit the mold of typical Steeler WR's..tough, physical guy, not afraid to go down the middle but capable of stretching the field too. With Hines not healing up as fast as he used to, you can see where this pick would make sense. Adding a guy like Sanders would seem to me that they are committed to continuing to pass the ball up and down the field and making sure they have capable guys ready to step in.
Again though, ignoring the defensive backfield which is a huge concern for me...