When the Bears selected Kellen Davis a TE out of Michigan St, most in our community were dumb founded by the move. With Greg Olsen and Desmond Clark locked in at the 1 and 2 spots, it seemed unusual to draft a TE just for blocking purposes. Surley they could find a blocker in FA or somewhere on the team.
As it turns out the Bears might have other plans in mind. While he may still see time blocking for Benson or Forte or Wolfe or Peterson, he might also see time at defensive end. Davis played both in college.
I haven't heard anything official, but here it states that Davis has said he'd be willing ot make a full conversion to the defensive side of the ball if asked.
Whether or not he makes a full conversion of spends time on both sides having a 6' 7" guy roaming around the line on passing plays and/or FG attempts could clog up some lanes.