Information does not "want to be free." The proposition is nonsensical on several levels, and someone as smart as Stewart Brand would never say something so foolish. The fact that he's been so widely misquoted is evidence more that information wants to be persistently misunderstood.
It's to Chris Anderson's credit that his perhaps unfairly mocked Free attempts to correct the record in this respect, although most reviewers don't seem to have read that far. What Brand actually said, at a 1984 conference, was this:
On the one hand information wants to be expensive, because it's so valuable. The right information in the right place just changes your life. On the other hand, information wants to be free, because the cost of getting it out is getting lower and lower all the time. So you have these two fighting against each other.
Anderson's book is an occasionally successful attempt to think through the economics of information when, as Brand says, "the cost of getting it out is getting lower and lower all the time." It's not as foolish or obvious as it seems; most of those mocking the book don't seem to have read it very carefully. But then again, neither do its acolytes and in some cases, neither has Anderson.
He rightly starts by pointing out that "free" has different meanings in English, encompassing two Latin words, libre, as in freedom, and gratis, as in free of charge.
(I have been watching the first season of Deadwood on DVD, and in my head I am hearing this wonderful exchange between Al, the saloon owner, Merrick, the newspaper editor, and EB, the wannabe erudite mayor:
Merrick: “The vaccine will be distributed gratis.”
Al: Free gratis.
Merrick: Free gratis is a redundancy.
EB: does that mean ‘repeats itself?’
Al: Then leave gratis out.
Merrick: What luck for me Al, that you have such a keen editorial sense. Free. Distributed Free. Period.”)
In any case, the confusion between "free" and "gratis" has always been a source of frustration to Richard Stallman, whose free software movement had very little do with money and very much to do with the free reuse and modification of code.
So Anderson correctly restates Brand's aphorism as "abundant information wants to be free. Scarce information wants to be expensive." Which means he's discovered that the most basic law of economics (the rarer something is, the more expensive it is) applies to information just as it does to everything else, along with the equally elementary idea that you can charge less and less for something as it gets cheaper to make and distribute.
That's not worth a book, and it's not what he spends his time on. He is also not proposing that no one needs to pay for anything anymore. The book essentially looks at how cheap or nearly free information can be used to drive a profitable business model of selling other information that is not free, or associated hard goods with large profit margins.
As something becomes commonplace, the decline in its price sometimes changes a lot more than how it's sold on its own. As Anderson rightly points out, the industrial revolution could be said to have been driven by energy becoming much cheaper. This didn't just mean that the makers of carriages had to charge less for them. It meant that things like trains were now possible. (An idea discovered, as he points out, in the early 19th century by a French economist who coined the phrase, "supply creates its own demand.") 
The music industry's problems, to some extent, can be seen as a failure to grasp this point. Charging $20 for 12 songs was always an outrage; the profit margins were obscene and almost never passed on to those actually creating the "information," the musicians. The record labels were able to do this because there was no alternative; now that there is, their businesses are toast, but musicians will always be able to make a living and perhaps will be better off without the disgraceful contracts and bizarre economics the labels imposed on them.
There's a completely different supply-and-demand curve that's changing, which is that of information itself. The Internet has made information much more accessible than it used to be, but it has not increased our capacity to absorb it; if anything the increasing flood of information and the multitasking it encourages have reduced our ability to truly process information. So the valuable commodity here, the one whose scarcity is not going to change, is our attention. Along with that goes "reputation," or "popularity," which might be defined as the ability of someone or something to attract attention.
This is Google's business, as Anderson rightly points out. Google is not free because of some magical change in economics, but because they've realized that while search itself is an abundant commodity not worth paying for, the attention of searchers is not. So they bundle up your attention and put a price on it, and sell it to people who want it. And they quantify reputation as well -- PageRank is, he says, "the currency of reputation online."
So the economics of search (and Documents and Voice and and and) is not new and hasn't been changed by technology. What changed was the ability to quantify attention much more precisely than was possible with offline media, to sell it in a real-time spot market, and to closely monitor its worth. And the problems of newspapers are to some extent like those of the record labels -- they're not dying because "information wants to be free." Newspaper readers never paid anything near the actual cost of producing newspaper content.
Newspapers are dying because their method of selling attention wasn't very good. The old saw, "I know half my advertising budget is wasted, but I don't know which half," is no longer true. Google and other online advertising systems provided the tools to tell which half, and to stop buying the worthless half. Whoops! Craigslist was inevitable; putting little text ads online and making people search for them is ridiculously cheap, and it works better with a big networked universe than in small print on paper.
One of Anderson's more insightful points is that the way to profit from cheap information is to figure out ways to squander things that once were expensive -- to "think like a dandelion" in Cory Doctorow's phrase.  While old media frets over the fate of every single allegedly valuable seed, dandelions hurl them to the wind, and most of them die, but there are dandelions absolutely everywhere. In other words, maybe it doesn't matter if some persistent people get the song/article for free, especially if the cost of stopping them drives away good customers or inhibits a smarter strategy.
Anderson does say some foolish things, often because he fails to distinguish between the cost of reproducing information and the cost of creating it in the first place. The former is indeed tending to zero in some cases, but the latter is, for the most part, not. He almost completely misses the point that businesses based on distributing information (record labels, for instance) are threatened by this but businesses based on creating it are not only unthreatened but perhaps aided by no longer having to contract with distributors.
What value does a major record label offer? The ability to produce large numbers of CDs that no one wants anymore, the ability to place those unwanted CDs on the shelves of the ever-dwindling number of record stores, and the infrastructure and money to pay off people to get music on the air. Of course they're in trouble! No one wants that, any more than we want the "services" airlines offer. Musicians and customers put up with it because they had to. And now they don't have to anymore.
"Companies make their money by creating an artificial scarcity in ideas through intellectual property law," he says.  Think about this for a second. It's utter nonsense. The "scarcity in ideas" is not at all artificial. There is only one U2. They only release an album every few years. There is a tremendous demand for what they do. It's not cheap to do it (leaving aside any of the superstar-entourage nonsense, just hiring a top-flight studio, paying people like Brian Eno and Daniel Lanois, rehearsing, recording, etc, is expensive) and nobody else can do it, Coldplay notwithstanding.
Copyright does not enforce a scarcity of ideas. It has nothing to do with ideas at all, or it would be called "idearight." It's copyright and it governs the ability to reproduce ideas that already exist. If U2 views its business as the sale of CDs, or even the sale of songs, then yes, they might be in trouble, although as Radiohead's experiment showed, not necessarily. But that's not their business and they are not in trouble and they'll continue to make tons of money. Because the scarcity of U2 -- U2 the working band, not U2 the back-catalog of old hits-- is not artificial.
Beyond that, his overlong explication of piracy versus legitimate sales is standard stuff, no more or less true of digital content than of handbags or perfume. He mocks New York Times editor AM Rosenthal for saying "the only thing that's free is what we do: information,"  saying that Rosenthal is "head-scratchingly wrong," but no, he's not, not entirely. The Times' information isn't free to produce, not by a long shot. What Rosenthal really means to say is, "We're not getting paid to produce this information like we used to." And yes, that's largely the fault of the Times, but not because their information "wants to be free." It isn't and cannot be, and if the Times keeps not getting paid for it, we won't have the Times anymore.
And Anderson never really answers Rosenthal's point. He goes on to list a bunch of straw-men arguments against the free model, citing things like the fallacy of believing that "the only way to measure value is with money." Well, Chris, no, that's not the only way to measure value. But it's damn well the only way to pay reporters. So if you want to rephrase Rosenthal's lament to say "We can no longer monetize the value our staff creates," that's fine, but the Times still has a problem and it's still not one caused by information "wanting to be free."
And he doesn't seem to be saying that Rosenthal should just shut up and take it. He does say that  the "give it away and pray" model of many newspapers is "no business model at all." So he agrees that Rosenthal should get paid for what he does, but through a more rational business model. That's not a radical statement and what it means, essentially, is that the Times will never be gratis.
Ultimately, the book falls utterly short of its title, but, to be fair, a book called "Finding New Ways To Get Paid In a Digital Economy" wouldn't sell very well. Perhaps with good reason; there's very little here you haven't read before. And you can download the whole thing for free on Anderson's web site anyway.