There is a new beta available for Skype for the Mac – version 5.4 which enables you to instant message your Facebook friends.
• See your Facebook wall directly in Skype
• Update your Facebook status
• Easily Like or comment on a Friend’s status
Skype to Facebook IM features
• See Facebook friends in your Skype contact list
• See when your Facebook friends are online
• Instant message with your Facebook friends direct from Skype