User driven news seems to have a different flavor than the stuff being put out by news media. The Pew study for a week looked at news from aggregators like Digg, del.icio.us, reddit and compared it with traditional news media.
A news agenda formulated by citizens would be radically different from that put together by journalists.
One of the biggest differences noted by the researchers was the emphasis put on a single story. While the mainstream media tended to revisit the same story from a different angle each day, users were happier dipping in to a variety of topics.
Not so surprising that I found this story from Digg which referred to this article in BBC. You can read more about Project Excellence from this report on journalism.org.
I think this is the beginning of another trend that may transform production and consumption of news dramatically.