There are some differences and improvements. The most obvious is the increased speed and stability. Additionally Mozilla Firefox 6 will also feature the domain name in the address bar.
In addition, version 6 is also supported by firefox HTML 5, the enhanced add-ons manager, new features for the panorama, and permission settings window.
Not only that, Mozilla also announced the features of mozilla firefox version 8. With version 8, users can prevent the emergence of the add-on that is not desirable. Users can specify the ubiquitous add-on you want to use and which are not used.