East Coast blogger Tyler Green seems to have it first, with the email from Getty chairman John Biggs:

To all Getty Staff:

I wanted to let you know before we send out our news release that the Board of Trustees of the J. Paul Getty Trust will announce today that Dr. Barry Munitz, president and CEO for the past eight years, has decided to resign, effective immediately. He indicated that he made this decision after lengthy consideration so both the Getty and he can move forward.

No severance package, and he must reimburse the Getty $250,000. Art historian Deborah Marrow, director of the Getty Foundation, will serve as interim President and CEO of the J. Paul Getty Trust. (The lack of severance is disclosed in the press release where Munitz says, "I will always be proud of my association with the Getty. I'm taking this action, after lengthy consideration, so both the institution and I can move forward.")

Big story, broken by a journalist who blogs. Biggs' email went out at 5:05 pm. At 5:11 Greene sent his email about the item being up at Modern Art Notes. The L.A. Times, which did breakthrough reporting on Munitz's management tenure at the Getty, followed with a website news alert.

Times compiles its Getty coverage

* Adds and edits made as the story develops

Previously:
Nailing Munitz
Reaction to Vanity Fair story