This article in the Washington Post generated this thread on Baseball Think Factory. I've posted an adapted version of my comment here.
I don't see the point of trading a veteran simply because he's got trade value. What you get back is equally important. Either it helps you or you don't do the deal.
Everyone wants the Nationals to trade Nick Johnson and to move Adam Dunn to first base. Dunn has shown no greater ability to play that position than left-field. If anything, he's looked worse. Johnson's injury history is going to count against him in deals, reducing his value to quarters on the dollar. And it's not as if the Nationals have a sure-fire can't miss long-term replacement in the organization.
Nobody talks about Cristian Guzmán much for reasons that are not quite clear to me, but appear to be related to fielding. Are these the same people who want to move Dunn to first? The Nationals actually do have a replacement in the organization for him, although it's a definite downgrade - Alberto Gonzalez, the former Attorney General. He definitely doesn't hit as well as Guzmán, and his fielding seems to be about the same.
The Nationals do have a surfeit of corner oufielders, including the aforementioned Dunn, but only Josh Willingham is at all marketable, unless someone wants Dunn. Nobody accepts Elijah Dukes' good behaviour represents a genuine conversion. (We'll know when they do when we start seeing articles about it in the paper.) Austin Kearns is playing too badly for his contract.
The Nationals have no depth anywhere else, except young pitching. If I were them, I'd see what I could get for Stammen or maybe Balester. But that would probably be an older guy like Nyjer Morgan again.