Earlier today, President Barack Obama formally announced the appointment of Denis McDonough as his new chief of staff and noted that the appointment "was the worst-kept secret in Washington." Here's the press conference video:

The president described McDonough as the "consummate public servant," "a great friend to me and to everyone who works at the White House," "an indispensable member of my national security team" and "a pretty humble guy."

"Nobody outworks Denis McDonough," Obama said.

The Atlantic has a profile on McDonough. You can read it here [1].