Obama has just rescinded the rule that would have let Bush's heirs continue to claim executive privilege over his papers:
The Executive Order on Presidential Records brings those principles [of openness and tranparency] to presidential records by giving the American people greater access to these historic documents. This order ends the practice of having others besides the President assert executive privilege for records after an administration ends. Now, only the President will have that power, limiting its potential for abuse. And the order also requires the Attorney General and the White House Counsel to review claims of executive privilege about covered records to make sure those claims are fully warranted by the Constitution.