Google News Report USA claims to “estimate referrer traffic to the source” from Google News.
Headlines from the Google News homepage are ranked according to “appearance day and time, prominence on the Google news page, number of appearances, and others.”
At the bottom of the page, the author also lists the top sources of articles appearing on Google News, New York Times and Washington Post are #1 and 2.
Not being so much a numbers person, I’m not sure how accurate this is. And, of course, its only an estimate of referrer traffic, not a ranking of actual traffic. But given how possessive newspapers are of their content, maybe this will show the naysayers that Google News can help their traffic instead of hurting it.