Watergate involved investigative reporting?

Over at the New Yorker, Steve Coll expresses his concern about the future of US journalism:

... how did we end up in a society where Williams College has (or had, before September) an endowment well in excess of one billion dollars, while the Washington Post, a fountainhead of Watergate and so much other skeptical and investigative reporting critical to the republic’s health, is in jeopardy?

I've got a different question, Steve: how did we end up with journalists who believe that the Washington Post did investigative reporting pertaining to Watergate?

... as Watergate unfolded from 1972 to 1974, media revelations of crimes and political misdeeds repeated what was already known to properly constituted investigative authorities. In short, carefully timed leaks, not media investigations, provided the first news of Watergate.... Watergate prosecutor Seymour Glanzer says that what really mattered – both legally and politically – was Nixon's failure to destroy his incriminating tape recordings, not the media's coverage: "Woodward and Bernstein followed in our wake. The idea that they were this great investigative team was a bunch of baloney." (source)

Basically, Woodward was a local reporter, and when the Washington Post was notified (!) of a burglary in town, this is how things happened in Woodward's own recollection:

... it looked like a local burglary at the Democratic Headquarters, a police story. I covered the night police beat. It was a Saturday morning, I think the summer. Editors looked around and thought, "Who could we call in? Who would be dumb enough to work on this story on a Saturday morning?" And they thought of me immediately.

Otherwise, Woodward seems to have merely written down what Deep Throat, his informant, told him, much as he simply wrote down what prominent people told him in his later books. Here's another question for you, Steve -- if Watergate is such a great example of investigative journalism, has Woodward revealed anything through investigative journalism since? It's been over 35 years...