According to developer Justin Bishop's blog post:
To make this work, we released new technology for developers so they can offer this option to you on other websites and applications. We work closely with third-party developers to enable intriguing and meaningful experiences both on and off Facebook.com. Since we launched Facebook Platform in 2007, developers have created 10s of thousands of applications to help you connect and share with your friends in interesting ways — whether by playing a social game, discovering new books or creating group greeting cards.
This is a big move for Facebook, which as I mentioned, historically kept a tight grip on it's information in order to drive users into Facebook to create more visibility for its social ads. Bishop's blog post indicates that there will be more ways to share information via more Web sites in the future.