Don't forget the CBA negotiations. If there's no CBA reached before the draft, then the draft will happen before the free agency period begins, and teams won't really know what compromises may be struck regarding the 2011 FA class. In that case, the Bears would have to draft as though the 2011 FA period didn't happen, because it's entirely possible that it won't.
One plausible scenario, for example, could be a CBA being struck around Sept. 1 once games start being threatened, with loss of 1-2 weeks of games, and a very abbreviated FA period where players are given huge penalties if they sign with anyone other than the team that controlled them the previous year.