Larry Johnson over at the No Quarter blog has an interesting take on the musical chairs going on in Washington, D.C. (WDC) in the upper levels of the national security community. Mr. Johnson (formerly with CIA as well as Department of State's Office of Counter Terrorism, according to his bio) writes a fairly "hardball" styled blog, which in my opinion suits this type of subject (i.e. bureaucratic/political gossip).
With the creation of the Director of National Intelligence and the shifts in power (i.e. budgets and authority) toward the military during the last ten years or so, there have been very real and significant changes in the US national security community. When you add the issues caused by the Iraq War, the War on Terrorism, and the merger of multiple organizations to form the Department of Homeland Security, it will be many years before things involving security, intelligence, and defense run smoothly again in WDC.