Looks like Facebook is also trying to dominate the desktop in addition to the mobile space, with a reported leak that has revealed a Facebook Messenger application for the desktop – meaning people are always-on even if they don’t access the social networking site.
While Facebook is trying to make an “official” application, there are many that do the same thing as Facebook Messenger – such as Digsby or Skype. In addition, if your IM has Jabber support, you can basically communicate with other Facebook users via that protocol as well. I sort of think that Facebook wants to compete head-on with the other instant messaging services like AIM and Windows Live Messenger – two big juggernauts in that field. So, it makes sense to have a “Messenger” app for that purpose. However, I don’t think it will succeed that far.
The app is also designed similar to the mobile applications, allowing you to see and accept new friend requests, see any new notifications and the live ticker that basically tells you almost every single minute-by-minute activity your friends have done on Facebook.