I'm using 5.0 right now. Its really, really fast compared to 4.0.

That's great improvement... I'll test FF5 during a following Week.

Almost three months following Firefox 4's release, Mozilla has posted final builds for Firefox 5 ahead of the official release date of June 21: https://wiki.mozilla.org/Releases#Firefox_5
The new accelerated release schedule Mozilla is using for Firefox development will see the next version of Firefox, Firefox 6, go into beta about two weeks following Firefox 5's release.

The new release looks and runs very similar to Firefox 4, but it has a few changes under the hood. The official changelog will be made available here: http://www.mozilla.com/en-US/firefox/5.0/releasenotes/

    

•    Support for CSS transitions has been added
      The preference for "Do Not Track" has been moved to aid easier discoverability by users
      Improvements for canvas, JavaScript, and networking performance, and memory usage
      Improved standards support for HTML5, XHR, MathML, SMIL, and canvas
      Improvements to spell checking for various languages
      Improvements to Linux desktop environment integration
      Performance improvements for background tabs
      WebGL fixes: a fix for cross-domain textures and a fix to address the memory stealing issue

While Mozilla is pushing out new updates for Firefox, it is also working on a plan to end support for Firefox 3.5, which is now almost two years old. Users that are still on Firefox 3.5 may see a forced upgrade to 3.6.18 in the coming days.

Download links are available below:

- Windows (32-bit): ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/5.0/win32/en-US/Firefox%20Setup%205.0.exe

- Linux (32-bit): ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/5.0/linux-i686/en-US/firefox-5.0.tar.bz2 or Linux (64-bit): ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/5.0/linux-x86_64/en-US/firefox-5.0.tar.bz2

- Mac OS X: ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/5.0/mac/en-US/Firefox%205.0.dmg

(NW)