The most interesting part of this (to me anyway) is his intention to drop the WSJ's subscription wall. I grew addicted to Marketplace and Tech sections of the Journal a couple of summers ago (when I had free access:)) and then over the next year when I ponied up for the student subscription.:)
Arrington does some sloppy math to come up with why this makes economic sense, and he's directionally definitely right! The WSJ will make more money.
The Internet economy is lucky enough to be powered by a strong externality: advertising. This isn't new: the same has always applied to newspapers. However, dropping the price of anything to zero (even something thats really cheap) will really push up the demand for the product through the roof, especially for a product like high-quality news for which the demand is extremely elastic.
Of course, Google can amplify the benefits of "free" because of the way search can be the source for many people finding content. Freeing up this high quality content makes it indexable, more linked, and hence even more likely to find new users.
Anyway, while I'm thrilled to be able to read the WSJ online, I'm also a little annoyed that there's no good example left of a site that doesn't rely completely (or dominantly) on the advertising externality for their revenue. Where's the web content equivalent of HBO? something that doesn't rely on maximizing distribution and hence advertising potential, but is able to charge consumers directly for (some or all of) its content?
"Content" may "want to be free" (how many times have you heard that?), and I expect that to be the dominant business model for most content on the Internet, but the latent contrarian in me is hoping that some contrarian examples emerge too...