Proclamation by Obama:
"As a mark of respect for the memory of Senator Edward M. Kennedy, I hereby order, by the authority vested in me by the Constitution and laws of the United States of America, that the flag of the United States shall be flown at half-staff at the White House and upon all public buildings and grounds, at all military posts and naval stations, and on all naval vessels of the Federal Government in the District of Columbia and throughout the United States and its Territories and possessions until sunset on August 30, 2009. I also direct that the flag of the United States shall be flown at half-staff until sunset on the day of his interment. I further direct that the flag shall be flown at half-staff for the same periods at all United States embassies, legations, consular offices, and other facilities abroad, including all military facilities and naval vessels and stations."
http://www.politico.com/politico44/perm/0809/proclamation_on_kennedy_7d03b96f-28fa-42a5-b67a-8062caa26e04.htmlUPDATE: Obama is to deliver the eulogy at Kennedy's funeral, according to Politico.