It seems Mozilla team is really hard working on Firefox's upcoming version 4.0 which is currently codenamed as 3.7.
A new sweet animation has been added to "Preferences" (Options) window which is currently disabled by default but can be enabled using "about:config" method.
How to Enable New Animation in Mozilla Firefox 3.7 (4.0) Preferences / Options Window? - Tweaking with Vishal
A new sweet animation has been added to "Preferences" (Options) window which is currently disabled by default but can be enabled using "about:config" method.
How to Enable New Animation in Mozilla Firefox 3.7 (4.0) Preferences / Options Window? - Tweaking with Vishal