The House Oversight and Government Reform Committee released its report (pdf) on PlameGate today. The last two paragraphs tell the story:
The investigation sought to answer basic questions about this incident, including (1) how the Valerie Plame Wilson leak occurred, including whether there was a concerted effort to knowingly disclose classified information; (2) whether senior White House officials complied with requirements governing the handling of classified information; (3) whether the White House took appropriate steps to address an improper leak and sanction any individuals involved; and (4) what legislative or other actions are needed to ensure appropriate identification and handling of classified information by White House officials so that such leaks do not occur in the future.
The Committee has been unable to completely investigate these matters, in part, because of the President's assertion of executive privilege over the report of the FBI interview of Vice President Cheney. This invocation of executive privilege was legally unprecedented and an inappropriate use of executive privilege. It prevented the Committee from learning the extent of the Vice President's role in the disclosure of Ms. Wilson's identity.