The main claim is this: "What the writer does is get right to the heart of the matter, in that no matter what form they might take, how formal or informal they might be, a blog that is produced by a company has is still at it's core a form of advertising. All that's different is the format of the ad."
To which I say: Baloney
It depends on how the corporation approaches blogging and what's done with it.
Clearly in some cases the advertising department might take ahold of blogging, and use it as a marketing/advertising vehicle. And clearly they're going to flub it because they don't understand the medium.
But, for example, consider the Adsense Blog where the staff that runs adsense posts helpful hints and ideas from time to time. If that's advertising it's highly buried.
A primo example is blogs.sun.com where Sun let the geeks loose to write "whatever they want" (within reason).