And the release notes ( http://www.mozilla.com/en-US/firefox/6.0/releasenotes/ ):
The latest version of Firefox has the following changes:
- The address bar now highlights the domain of the website you're visiting
- Streamlined the look of the site identity block
- Added support for the latest draft version of WebSockets with a prefixed API
- Added support for EventSource / server-sent events
- Added support for window.matchMedia
- Added Scratchpad, an interactive JavaScript prototyping environment
- Added a new Web Developer menu item and moved development-related items into it
- Improved usability of the Web Console
- Improved the discoverability of Firefox Sync
- Reduced browser startup time when using Panorama
- Fixed several stability issues
- Fixed several security issues
I haven't tried Firefox 6.0 myself, however, the first item “The address bar now highlights the domain of the website you're visiting” is nothing new. Internet Explorer and Chrome have had that for quite some time.
UserAgent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.19) Gecko/20110707 AlexaToolbar/alxf-2.13 Firefox/3.6.19


