Facebook has updated its search functionality significantly, the basic aim of which is to encourage public conversation.
The jist of it is this: you can now search popular stories and what people are saying about them, both your friends and public figures. For example, if you search "Canada Election", an option to read 1,000+ posts about it pops up. Clicking it, you'll see a variety of news articles about it, and posts from public figures and your friends (if they're talking about it).
Facebook says this is a "first step" and it will continue to develop and improve on search functionality.