The Washington Post has now confirmed that Mark Felt, a former FBI official, is the notorious Deep Throat.

Addendum: Here's a link to the Vanity Fair story.

An excerpt from the WaPo story:

The confirmation came from Bob Woodward and Carl Bernstein, the two Washington Post reporters who broke the Watergate story, and their former top editor, Benjamin C. Bradlee. The three spoke after Felt's family and Vanity Fair magazine identified the 91-year-old Felt, now a retiree in California, as the long-anonymous source who provided crucial guidance for some of the newspaper's groundbreaking Watergate stories.

The Vanity Fair story said Felt had admitted his "historic, anonymous role" following years of denial.

In a statement today, Woodward and Bernstein said, "W. Mark Felt was 'Deep Throat' and helped us immeasurably in our Watergate coverage. However, as the record shows, many other sources and officials assisted us and other reporters for the hundreds of stories that were written in The Washington Post about Watergate."

Felt's guidance to Woodward -- provided on "deep background" in secret meetings -- helped keep public attention focused on the June 1972 break-in at the Democratic National Committee headquarters in Washington's Watergate office and apartment complex, and on a subsequent cover-up effort. This ultimately led to a congressional investigation that revealed the role of Nixon and a number of his top aides. Under threat of impeachment, Nixon resigned in 1974.

Alan Bass, CAJ-L's moderator, pointed to an Alternet MediaCulture blog posting. I liked what it had to say:

It's ironic that America's most famous single, anonymous source should surface at a time when single, anonymous sources hostile to power are being castigated...

However, if I remember my readings on Watergate, the dynamic duo of Woodward and Bernstein had to follow a two-source rule: If they were going to use an unattributed quote or fact, it had to come from two independent sources who were in a position to know.

Anyway, for more background on Watergate and Deep Throat, check out this Wikipedia posting. It's already been updated with the Felt information.