Yesterday I had the same conversation I've had a dozen times, about whether or not journalists should link to external sources of news. The journalist on the other side of the phone was complaining about websites that act as "aggregators." I applauded them.
The best phrase I've come to explain this is that "providing good links is an editorial service." The Newspaper Next blog says it best:
Our users control how they spend their time. They always did and they always will. We need to give them value and links have value.
This fear that people will never return to our site if we send them away becomes a self-fulfilling prophecy. Refuse to give them what they need and they will go away in frustration rather than because they clicked a helpful link. If they click a helpful link and find the answer they were looking for or some information that helps them understand your story better, they will remember that you provided the answer, even if it came from someone else. And they will come back to you for more answers.
Another mantra that comes to mind, from Jeff Jarvis: "Do what you do best, and link to the rest."
At NewsTrust we create what I like to call "tasty hyperlinks." We like to think they are so tasty that people who use them will come back for more. We don't just filter news by topic - we add one more layer of value by filtering the news by journalistic credibility. David Weinberger points us to examples where other news organizations are obviously failing to meet the same criteria. We believe the top links we send out at NewsTrust solve various problems that we now face as a society living in a networked world with arguably too much information.
The key to this success is community - no one person can sort through all the journalism that comes out every day. It takes a community of people shouldering that responsibility. But that, my friends, is a post for another day.