DraftExpress is one of the best sources of information on prospects and the NBA Draft, and they have just released their first post-lottery 2011 NBA Mock Draft. They have the Bulls getting some help for their backcourt, and a surprising pick for their front court with their two first round picks. With the 28th and 30th picks in the draft, they have the Bulls taking Richmond's Justin Harper and Duke's Nolan Smith respectively.
Harper is a power forward who can stretch the floor, but with Taj Gibson's recent emergence, you have to question whether or not backup power forward is a serious need. But Gibson might be playing himself into a more expensive contract than the Bulls can afford for a backup, so they would be wise to bring on an insurance policy in case he elects to sign a lucrative deal elsewhere.
Nolan Smith has the ability to play both positions, but his size might limit him to a point guard in the NBA. He would likely be an upgrade over C.J. Watson, and a solid backup point that the Bulls can count on. Without a lot of holes on their roster, this would be a good luxury pick.