From the NY Times article:

"Today, George Tenet, the director of the C.I.A., submitted a letter of resignation," President Bush said on the South Lawn of the White House in an announcement that stunned Washington by its timing. "I met with George last night in the White House. I had a good visit with him. He told me he was resigning for personal reasons."

While Mr. Bush said he had told Mr. Tenet he was sorry to see him go and that he had done "a superb job on behalf of the American people," there was immediate speculation that there was much more behind the departure than Mr. Tenet's wish to leave the demands of an admittedly taxing post he has held since 1997...

...Mr. Bush announced the resignation of the 51-year-old Mr. Tenet in a way that was almost bizarre. He had just addressed reporters and photographers in a fairly innocuous Rose Garden session with Australian Prime Minister John Howard. Then the session was adjourned, as Mr. Bush apparently prepared to depart for nearby Andrews Air Force Base and his flight to Europe, where he is to take part in ceremonies marking the 60th anniversary of the Normandy invasion and meet European leaders — some of whom have been sharply critical of the campaign in Iraq.

But minutes later, Mr. Bush reappeared on the sun-drenched White House lawn, stunning listeners with the news of Mr. Tenet's resignation, which the president said would be effective in mid-July. After that, Mr. Bush said, the C.I.A.'s deputy director, John McLaughlin, will be acting director."