Do We Need 'Professional' Bloggers?

In her Megnut column at O’Reilly Net, Meg suggests that the time has come for companies to hire professional bloggers to project their news and outreach into the blogosphere:

It’s time to take blogging to the next level and that starts with paying people to produce high-quality, focused blogs for commercial Web sites. Until that happens, people will continue to view Weblogs as little more than personal diaries, or just another form of Usenet. Until we create a financial structure to enable the creation and maintenance of professional blogs, we won’t see the best, next generation of Weblogs.

I’m not sure I agree with this, exactly (and I see from my aggregator feed that Dave Winer has his doubts as well). For one thing, I don’t see how this would differ from someone in the marketing department of a company maintaining the What’s New page for their public-facing site.
If the difference is in the quality of the writing or some intangible expertise of the blogger, then aren’t we once again confusing the medium for the people who happen to be using it. Does blogging make good bloggers or do good bloggers take it upon themselves to make their blogs?
I’m not saying there can’t be a business model or even a professionalism attached to blogging, but I think this bears more thought. Otherwise, it’s a little like saying that each company should hire an opinion editorialist or a librarian. These might be good ideas in specific cases but the argument breaks down when taken as a generality.
Underlying Meg’s point seems to be another important one, the question of sustainability that has come up after each successive wave of Internet enthusiasm. As the size of the blogosphere grows and the novelty wears off, will people continue to do it for free or for the tangible benefits of notoriety or “thought leadership”?
I know that for me blogging solved an earlier problem: the tedious work of updating my web pages scaled up in a linear way with the size of the archive, so the blog mechanism reduced the friction associated with refreshing a site. Of course it did not eliminate the effort entirely, but the labor that remains is much more focused on the writing process and the content itself.
Still, as the scale continues to grow (not just for me personally, but taking all blogging together) even the slightest amount of friction can be like that grain of sand in your shoe on a ten-mile hike. And when it’s no longer fresh or cutting-edge or maybe when it isn’t as much fun anymore, people blogging voluntarily will opt to stop.
If it’s your job and it isn’t any fun anymore, that’s a whole different problem.