Although Facebook Messenger for Windows leaked in late December, it's now officially available through Facebook's website. If you don't see a Download button yet, don't worry—the app will roll out to all users over the next few weeks. As far as we can tell, not much has changed since December. There are still Chrome-esque conversation tabs, navigation buttons taken straight from the mobile site, pop-up notifications, and News Ticker support. The screenshots Facebook used in today's announcement are even the same ones you'd find on the Facebook Messenger Help Page, which has existed since the app originally leaked.
According to Facebook, the previous version of Messenger was "a test," and is now rolling out to everyone. Also, a Mac version is on the way, but the company declined to give us a timeframe for that one.
Notable absences from the app are video chat (through Skype) and group chat, which Facebook touts inside its web interface. This puts Facebook Messenger for Windows on par with Messenger for iOS, Blackberry, Android, and Windows Phone. The only features that make Messenger for Windows worth using (versus just plugging your Facebook credentials into an IM client like Adium) are its interactive News Ticker and Notifications inbox.
While Facebook Messenger isn't yet positioned to replace text messaging (or video chatting) as some have speculated it might, a desktop app goes a long way towards making the social network an even more viable platform for short form communication.