As much as we don't like paying for content, someone has to pay for for the journalist to do their job. If that can be done through ad money, great. These big mega news corps have found that putting content online ain't cheap. Adding any channel costs money and if the ROI isn't there the channel dies.
I would be interested in the number of *journalists* the sites above have employed. Some do I am sure, but news usually has to bubble up to these purely online news sites which usually comes from places like the NYT (think slashdot).
I'm not saying money can't be made via free online content, but having close ties to the news world, I can say with confidence that they are hurting. It's an industry shift that started with the Internet and will continue until most content is purely online. How much will this content cost? I have no idea, but someone will pay for it.