It's available at Archive.org(luckily!) under a CC-BY-NC-ND license.
Incidentally, the book used to be downloadable from Bloomsbury Academic page under a CC-BY-NC license but it's a broken link now. See why we need a library? :)
I didn't have time to read the book then, and there's a few other books on my read list right now. Meantime, I gathered this much from the following blogs/ online posts (there are mixed reactions, basically):
From Mr Tunes (Dec 2008):
In my opinion, if Lessig cut a bit of repetitive text about the Open Source software industry out of the book, and maybe shaved off about fifty to one hundred pages or so of other fluff content, I think he has a real winner on his hands.
I would recommend this book to any musician, filmmaker, or other artists, as well as to anyone who is interested in copyright law. But for the average person this book might be a little much. 7/10
From The Independent (Nov 2008):
Thankfully (and I'm writing as a rights-holding musician here), Lessig isn't anti-copyright. He only wants it to apply sensibly – particularly in this dynamic new environment, where the circulation of culture is operating at light-speed. Some of his broad solutions are pretty familiar to artists. He wants to take the principle of the "performers royalty" for radio – invisible to the audience who listens for free, but which all stations pay – and extend it to internet service providers as a whole.
Remix brilliantly puts a name to those businesses trying to bridge the gap between the commercial (Amazon) and sharing (Wikipedia) aspects of the web: the "hybrid" enterprise. Their looser, less paranoid approach to copyright allows fans to explore their enthusiasms. Lessig cites many studies – Warner's U-turn around fan usage of Harry Potter is a prime example – to show the commercial benefits this brings.
I don't quite go along with his general enthusiasm for "remixing" as an art form. Musicians who explore harmony, melody and rhythm might ask: is it more important to play and compose a new soul riff, for new times, than just rest on the auratic power of a James Brown sample? But Lessig is surely right that digital culture requires governance that is more subtle and ecological, judging a balance of forces between commerce and community, than precise and draconian. The Democrats could do a lot worse than give the formidable Lessig some work in this area.
From Businessweek (Oct 2008):
It's nice to see Lessig trying to move beyond the mere critique of the system that he offered in previous works. He first stepped down this path a few years ago by helping to found the Creative Commons, a copyright-licensing system that has since become a powerful alternative to America's traditional copyright regime. And for those who have never read Lessig, the new book is a good primer on the shifting debates over copyright in the Digital Age. But Remix is Lessig's weakest effort to date, a derivative essay that rehashes a lot of his older work. Like Martin Scorsese doing another mobster flick, Lessig seems uninspired, groping for a fresh take on familiar themes. Most annoying, he devotes only the last 35 pages of the book to his reform plan, and some of those ideas are not even that new.
From The Complete Review:
Remix is a very approachable read, Lessing laying out the legal and economic issues in most basic style, heavy on the real-life examples. The simplification can get a bit annoying -- though it's good enough as a starting point for discussion -- and the anecdotes tiresome, and Lessig's parenthetical asides, while amusing, make it all seem a bit glib, but the basic point is an important one, and if this makes the books more accessible to a greater number of readers and gets them to think about (or pressure their government representatives !) to reform copyright it's worth it.
Have you read the book yourself?