Many people have complained about the new Facebook Chat system. While for people who dislike using it for instant messaging like me, turning it off would solve the problem. For those who depend on it, then they are probably annoyed by the fact that you can longer view your friends according to your friends list.
How to Get Back the Old Facebook Chat
To get back the old Facebook chat, you can go online (tick Available to Chat) on your main Facebook window and tick “hide sidebar” via the settings icon. Then, open up a new tab/window and go to http://www.facebook.com/presence/popout.php It is the pop-up window of the old Facebook Chat. It should work for now, before FB team decides to remove it.
If you’re getting really annoyed about it, then just Go OFFLINE, untick available to chat.