The best example that comes to mind is that of the United States. We have case law in the United States going back to the 19th century allowing fair use, as it's called there, as a defence, but it wasn't until the 1976 revision to the Copyright Act that they actually codified it. The feeling was that this was the common law that's developed. It makes sense to have the legislation harmonized with the actual common law as much as possible, just to create certainty in the minds of end-users and institutions who have to try to order their affairs to comply with fair use.
The four fair use factors you see in the United States are based on how, in 1976, Congress saw the state of the law. I think that would be very similar to doing what the court in CCH said. The court in CCH did not pull these six factors out of the sky. There was a very long analysis in the court of appeals decision in 2002, which looked at a lot of English case law and developed these six factors. Basically, the Supreme Court said it endorsed those six factors.