We just noticed a popup on the chat side-bar inside Facebook, whilst using a Windows computer to test our Copy & Paste Memes for Facebook Chat application before releasing the first full version.
It appears that Facebook have just released their standalone messenger app for Facebookers using a Windows operating system.
The application allows users to chat with their Facebook friends in a simple tabbed interface, to check their news feed and delivers notifications directly to the desktop.
To get the application today simple head to the Messenger for Windows landing page.