Firefox 3.6 Beta 1 review

Personas Support Built-in.
...simply visit Mozilla Add-ons, and go to the recently added Personas section. Personas are live previewed as you hover on the thumbnails, and become permanent when you click on Wear It.

Tabbed browsing Previews
...Tab Preview, though it’s turned off by default. To activate it, you must set browser.ctrlTab.previews to true via about:config. After that, when you press Ctrl + Tab to switch tabs, you get a horizontal line of tab thumbnails.

about:
..special about: pages have been added.
about:support, should become a troubled user’s best friend as it provides a helpful page with most details of your current Firefox settings including version number, customized preferences, and installed extensions; all of which can be easily copied to a support forum, email or chat window.
about:memory, is a first try on providing details about the current Firefox memory consumption.

Usability
Native videos now have a full screen option: right click on a video and select Full screen. On related news, a new full screen button is now available to add to the toolbars.

Internals

Further Windows 7 integration

Read the full article for all details: Mozilla Links
http://mozillalinks.org/wp/2009/10/firefox...-beta-1-review/