Tonight, Facebook has started testing a major revamp to Facebook search that promises to bring what many users and marketers have been clamoring for for a long time: live search of the News Feed and the public timeline.

Unlike the current Facebook search, which is pretty clunky in the way it organizes results, the new Facebook search is all about searching recently posted updates and content. Now, when you search on Facebook, you’ll get two sets of results:

1. Most recent posts by your friends
2. Most recent posts by all users who have made their profile open to everyone (including public profiles)

For example, here’s what a search on “Iran” would look like tonight:

If that looks very similar to Twitter Search, that’s because it is. However, the new Facebook search differs from Twitter in 2 important ways:

1. Updates from your friends come before updates from everyone.
2. All updates contain rich content in-line, from videos to music to thumbnails of shared links.

It’s important to note that updates from friends are usually private, and not on the public timeline. Although Facebook is making public timeline search available for the first time ever, it is still prioritizing communicating with friends above searching the public timeline in this iteration of Facebook search. Facebook CEO Mark Zuckerberg told Inside Facebook earlier this year that the future of Facebook lies in a hybrid public/private sharing model.

Nevertheless, this marks a major step forward in the evolution of Facebook’s search services. Now, marketers and analysts will have another tool to monitor conversations on Facebook in addition to Facebook’s Lexicon tool, which only shows trends at a very high level. Facebook started allowing users to open up their profiles to everyone in March, in an attempt to better serve users who want to share their updates more openly as opposed to using Facebook’s robust privacy controls.

Facebook also has a search partnership with Microsoft, who also owns a 1.6% stake in Facebook, but we’re still awaiting word on whether Microsoft is contributing any search technology to the new Facebook search.

Facebook says the new version of search is open to only a “fraction of a percent of the people on Facebook” as it tests out the new features. We’ll keep tabs on how testing goes and let you know as Facebook rolls out its new search service more broadly.