Lawrence Lessig was among the leaders of the move to disallow the copyright extension act. In fact, he was the main arguer of that viewpoint before the Supreme Court. As I've mentioned, I disagree with the notion that public domain is usually in the public good, so I'm more or less on the opposite side to Prof. Lessig. But in today's New York Times, he proposes a compromise move which sounds eminently sensible to me. Here's a link to it.