I don't think that the newspapers are treasonous, or doing this solely in an effort to thwart President Bush (i.e. I don't think that a Democratic president would be getting a free ride right now). That doesn't mean that the impacts of what they are doing doesn't damage the country, put lives at risk, or negatively impact President Bush's effectiveness.
I think, in simple terms, that they have forgotten that they are citizens, and that they have an obligation to the polity that goes beyond writing the good story. I don't think they are alone; I think that many people and institutions in the country today have forgotten they are citizens, whether they are poor residents of New Orleans defrauding FEMA or corporate chieftains who are maximizing their bonuses at the expense of a healthy economy.
I think that they're offended at the notion that citizenship might involve obligations to do something other than what you want to do anyway. Read the whole thing.
UPDATE: Jon Henke: "My question is: is there any legal line, any classified information at all, that the press could/should be prevented from, or held legally accountable for, disclosing? And if so, how and where do we draw that line?"
I think we've done it already, by statute. We've then modified that, rather harsh, line with a lot of unwritten understandings that used to work, but that don't anymore. I suspect that the New York Times is in theoretical violation of those statutes, but I also doubt that it's likely to actually be prosecuted. Its reporters may well be subpoenaed and ordered to identify the leakers, but the press enjoys no special privilege against such things. I think the New York Times will also experience considerably more general hostility, and further erosion of its former position as the "newspaper of record" as a result of this behavior, but that seems fair to me.