It seems significant that The Economist isn't just talking about the popularity of Wikipedia, but about how Wikipedia works and how the ongoing debate might impact its future.
The other week I actually heard a novelist, who ought to have known better, proclaim that "everything is on Wikipedia". I'm a fan of it myself, generally speaking, and have been inclined to think that traditional reference publishers blaming Wikipedia for their own misfortunes is less a reason than an excuse.
On a lighter note, has anyone noticed the tendency among Wikipedia's non-fans to refer to it as "the Wikipedia"? Correct usage, to be sure, but whatever the outcome of the rest of the Wiki Wars, I'm afraid that that particular battle is lost.