A half-hearted argument for licensing journalists

One of the charms of print journalism -- historically, at least -- is the perception that anybody can do it. Many famous journalists never actually studied it formally, and the story about the kid who starts out working the press and eventually breaks the big story never gets old. Of course, these sentimentalities should have little or nothing to do with the argument as to whether journalists should be licensed.
There are a few reasons I can think of why we shouldn't license journalists. One, there really isn't a point. Is there an epidemic of poor journalism going around in America right now? Even if there were, what kind of test or licensing would really fix it? Would Jason Blair not have been able to pass a basic current events/ethics test? I think there's no doubt he would have. Not to knock down the profession a knotch, but how can we really compare journalism to medicine, law or even plumbing? There really are very few basic requirements. Those include telling the truth and attempting to be fair. That's basically it.
We can talk about our role as gatekeepers, as watchdogs of the government, as forums of democracy, but none of those are really requirements to be considered a journalist. Otherwise sportswriters, fashion editors and designers would be out of luck.
The second and more pressing reason not to license journalists is the angry confused public reaction that would undoubtedly follow, not to mention the level of acidic debate it would necessitate within the journalism community. Journalists, already unpopular figures according to all the latest polls, would be further villified by bloggers, who, even if included as possible licensees, would overwhelmingly disapprove of any attempt to further centralize the media. Licensing would be met with skepticism, doubt and conspiracy theories -- none of which would probably be worth treading through.
But there is legitimate reason for licensing journalists, and that's to legitimize shield laws. As we all know, journalists go to jail occasionally for refusing to reveal their sources in the face of judicial subpoenas. The most recent examples have been Judith Miller, who outed Valerie Plame, and the two San Francisco Chronicle reporters who investigated Barry Bonds and baseball's steroids scandal.
The problem isn't quite as widespread as you might think from the amount of coverage these jailings tend to generate, but it does exist, and it is a concern, especially for those of us who plan to enter the profession. There should be no ethical dillema between informing the public and keeping a source hidden. The two should be parallel goals, not exclusive.
Further, I personally don't believe licensing is necessary for Congress to pass a federal shield law. I think bloggers, writers, tv reporters, columnists and whistleblowers should all be protected -- with limitations -- from being forced to reveal sources in the face of jail time, whether they possess some sort of license or not. But licensing might not be a bad idea to help facilitate the whole thing. By licensing, I don't mean that we should force anybody who practices journalism to take a test, I just think that for anybody who wishes to be under the protection of shield laws, it might be a good idea, if only to get some swing voters firmly on the side of shield laws.