All of a sudden, Deep Throat doesn't seem like the legendary hero everyone thought he would be. The fact that the FBI's number two guy would run off to the press to force Nixon to resign rather than investigate the manner themselves seems more like a devious act rather than one of courage.
Why? The FBI was having their own secret war against the Nixon Administration. J. Edgar Hoover had died just a month before Watergate happened, and the Nixon Administration was trying to gain control of the bureau. As Slate.com's Thomas Noah stated, the acting FBI director, L. Patrick Gray, had passed FBI Files on the Watergate case to Nixon White House Counsel John Dean. Felt was also sore due to being passed up for the FBI Director spot. All of these things compelled Felt to become Deep Throat.
The irony of the whole Deep Throat saga was that Felt himself was convicted for bypassing warrants while investigating the Weather Underground organization in 1980, and was eventually pardoned by Ronald Reagan. Hence, Felt received a taste of poetic justice in that instance.
Don't get me wrong; that doesn't mean I'm defending Nixon. I'm saying everything about Watergate - from the break-in to the dirty FBI tactics onto Woodward and Bernstein's blatant lies about Deep Throat's characteristics - stinks. Watergate was a dark time in the history of this country, and despite the media circle jerk that went on at that time and even to the present there is nothing positive that happened. I'm glad the obsession is over, and hopefully we can move past that chapter.
UPDATE: I've been doing some web surfing, and here's a good piece by Mark Russell from 2001 pointing to Felt. Felt being Deep Throat isn't that big of a surprise since a number of people knew Felt had been a leaker to the press prior to Watergate. Also, Thomas Mann had fingered Felt as Deep Throat in 1999.