This was inevitable if the US wanted to keep its place as one of the leaders of the internet. The web wants to be free, and if the US had decided to make sites accountable for libel, the sites would all just move out of the US.
It's becoming harder and harder to find countries with governments sympathetic to freedom of information. If the pirate party ever got off the ground, I could see a massive opportunity for people to create sites that share information in the way that YouTube did before it got bought by Google. That is, without real worry about copyrights.

Imagine being able to watch a lower quality version of a DVD before you decided to buy one. Not happening with our lobbyists, but with a different set of lobbyists...