A pair of top political reporters, John Harris and Jim VandeHei, quit The Washington Post last week to join an Internet-based news organization in Washington, D.C. They are the most prominent journalists to have joined the gradual migration from newsprint to the Web since Michael Kinsley started Slate.

There is, of course, no stampede to populate the new territories of journalism, no more than England and France emptied out to fill the North American continent after 1600.  Yet a steadily growing number of talented and knowledgeable news professionals are finding employment in online media and creating new opportunities for others.

The latest start-up is simply another sign that the Web is adding a large new sphere to the news business. Having lived and worked in this space for nearly five years, I am confident on a few points.

• The threat of entry by new competition is very real: Harris, 43, and VandeHei, 35, will join a start-up Washington newspaper called The Capitol Leader, backed by Allbritton Communications, which had, for a time, been proprietor of a now defunct broadsheet of good reputation, The Washington Star (it was the city’s leading daily until the Post overtook it in the 1960s).  The two journalists immediately contracted to appear regularly on the CBS television network (Allbritton owns a number of ABC-affiliated television stations, including its Washington outlet). Their paper will compete with two well-established political dailies, Roll Call and The Hill. But the heart of the new enterprise will be an as-yet unnamed Website, similar, perhaps, to The Hotline (owned by National Journal), The Note (owned by ABC) and other online portals that in recent years have modernized political coverage by agglomerating and commenting on it. Some new businesses can grow quite large. The all-time champion entrant in new media is Michael Bloomberg, now mayor of New York and potential presidential aspirant, who, starting in the 1980s, turned a database of bond prices into a media juggernaut to rival Dow Jones and The Wall Street Journal. With 1600 editors and reporters in 94 bureaus around the world, Bloomberg says it is the third largest news organization in the world, after the Associated Press and Reuters.

• Advertisers are genuinely confused by the advent of the digital age. They have been spending evermore heavily on online advertising, hoping to discover audiences whose responses they can monitor with some precision.  Classified advertising, especially help-wanted and houses for sale, near-monopolies for daily newspapers for more than a century, have been especially hard-hit. Consolidation in the once-exotic world of trade magazines has been the rule. Significant revenues from other categories may eventually return to newspapers, magazines and broadcast entities, when new media segmentation is better understood.  But never again will things be the same.

• Newspapers are on the verge of reorganizing dramatically to meet the changing circumstances. The second-largest U.S. newspaper chain, Knight Ridder put itself up for sale last year and was partially dismembered by its new owner, the McClatchy Co. Tribune Co., publisher of the Chicago Tribune, the Los Angeles Times, the Baltimore Sun and several other papers, soon may do the same, perhaps retaining ownership of the Tribune. The New York Times probably at some point will seek to buy back its shares from the public, selling off its other newspaper holdings in the process, including The Boston Globe. What the Bancroft family chooses to do with its controlling interest in The Wall Street Journal is anybody’s guess. Only The Washington Post seems secure in Graham family hands. Whoever they may be, the new owners of the distinguished metropolitan papers ­ the Philadelphia Inquirer, the L.A. Times, the Tribune, the Globe and others ­ may look to the Post’s stick-to-its-last) newspaper business model for inspiration (and hope to diversify as successfully as has the Post, with its cable television holdings and surging educational services subsidiary, Kaplan, Inc.)

• Journalism itself is alive and well. The inevitable tendency is to confuse the well-being of the journalist with the well-being of the field. Many highly-experienced practitioners have retired or gone into other businesses. Those who have replaced them are sometimes incompletely socialized in the traditional values of objectivity, fairness and public service. Yet an astonishing amount of good journalism is produced, especially when new media are included: more than anyone has time to read. (For instance, has anyone recently sought to compare coverage of the private equity industry in The Wall Street Journal with that of the weekly The Deal?) Cross-boundary communities of peers gradually will re-emerge, through competition, citation, press criticism and prize contests, to sort out the best disinterested journalism from all the rest.

Among new media, none are more interesting or more unfamiliar than the blogs. Five years ago, these “web-logs” didn’t exist.  Today, enabled by new technologies that make polished-looking self-publishing a snap, they are populous and, in many communities of interest, including economics, growing at a rapid rate. The innovation known as a blog-roll, the series of links along the side of a page (“in the rail”) that locates it within a self-defined community of other blogs, has become a powerful recommendation system, establishing a overall pecking order among sites. (The most widely linked are the most widely read, and the most widely read become, in effect, “best sellers.”) RSS feeds and other automatic syndication systems make it easy to at least see, if not actually read, what appears on hundreds of sites ­ each of them a little stream of opinion and information all its own.

And there’s the rub, of course. Bloggers’ motives are hard to aggregate, sometimes hard even to discern.  Many possess a fundamental political bent and aim to persuade. Others are the spontaneous expression of an ebullient personality and seek to share. Some exist mainly to promote a particular book, or magazine, or service:  they are a continuous free sample.  Most sites are supported by little more than habit, although some attract advertising and a few have their fixed costs born by an organization.  One of the most interesting pages, for example, is EconLog, where, bankrolled by the Indianapolis-based Liberty Fund, economists Arnold Kling and Bryan Caplan hold forth. The weekly Economist started a new blog this month, Free Exchange, overseen by Robert Cottrell and featuring the very funny Megan McCardle, known to readers of her Asymmetrical Information blog as Jane Galt.

The Web can be confusing: not everything on it is a blog.  It was from Greg Mankiw’s blog that I learned about William Nordhaus’ appraisal of the British Treasury Department’s Stern Review of the Economics of Climate Change. Mankw in turn learned about it from Tyler Cowen’s Marginal Revolution. But I suspect the main reason that the review Nordhaus posted on his Website took the form that it did was that he had been commissioned by the New York Review of Books to assess the report.

In other words, the article on Nordhaus’ Website is journalism of the highest tone, but it is journalism supplied by an economist. Economic Principals is journalism, too, but it is committed by a journalist. What’s the difference? By definition, a journalist’s standing (whether economic, political or anything else) depends on the willingness of readers (and other journalists) to support his work, not on members of the profession whom he covers. EconomicPrincipals.com, which is supported by readers’ subscriptions, describes itself as a weekly, not a blog.

It is hard to read more than a few economic blogs on a regular basis, at least if you have a day job. To my inner ear, they are too often the written counterpart of radio talk shows. The best sampler of them is still Economics Roundtable, moderated by University of North Carolina professor William Parke, which takes note of around 6,000 entries per month.  A fledgling wiki for economic blogs has appeared as well.  In this abundant world, the role of publishers and editors is more crucial than ever, in contriving scarcity for the benefit of readers, whose time is short. That’s why, when all is shaken out, newspapers and books will remain our most important sources of provisional truth.