Today's Washington Post had an article about federal government agencies leaving the Washington, D.C. area.
While not reported in the article, the FBI's FOIA Office (my former employer) is following this trend, and is in the process of moving to Winchester, Virginia. The FBI said in the local Winchester paper (registration required) that there are a number of reasons for this move. However, for the short term the move has disrupted FOIA operations and has caused long term employees to decide whether or not they are going to move. Additionally, as many of the offices moving still have to deal with FBI and Department of Justice Offices staying in D.C., the move may cause delays in administrative and litigation matters these offices are responsible for. Thus, only time will tell if this move helps the FBI's overall FOIA operation.