Update: Firefox 9 is now officially released. You can check for the update within the browser or read below to manually download.
Firefox 9 will be released officially anytime now, but for the impatient souls like me, Mozilla has made available the final version of Firefox 9 on their FTP servers.
Another major improvement in Firefox 9 is the addition of “two finger swipe navigation” in Mac OS X Lion. Also the theme integration for Mac OS X has been improved. Check the change log below
Improved theme integration for Mac OS X Lion
Added two finger swipe navigation for Mac OS X Lion
Added support for font-stretch
Improved support for text-overflow
Improved standards support for HTML5, MathML, and CSS
Fixed several stability issues