Well, of course, they did. And the actual marketing model has not changed, nor is it likely that a subscription newspaper, even if presented over a digital medium, will compete successfully with a "free" one - the only difference will be the methods of presenting the advertisement and collecting the cash. It is, and always has been, quite feasible for a newspaper to depend entirely on advertising income - the "free" weeklies are proof of this - just as their broadcasting counterparts do. In short, nothing has really changed all that much, and those newspapers who are careful enough not to price themselves off the market will do just fine. Those who insist on forcing a change in marketing just because the medium has changed, in the hopes that the world will change in their favor, will go broke.
Bloggers can cite and paraphrase and discuss articles in proprietory pay sites to the point where the public basically knows what those articles say. They can push the discussion forward beyond what the proprietory sites publish. If you want the cold, hard details, you'll have to pay for them, or at least go to a library. Otherwise you may not miss much.
There is a downside to the pay strategies. Proprietory materials don't get as much visibility or discussion, so magazines and newspapers can charge their way out of public debates. I'd imagine that when the New Republic put most of their articles on a pay subscription basis, a lot of people stopped bothering with them.