me acabo de dar cuenta, esta en ingles.
Firefox 3 Beta 1 Release Notes
Released: November 19, 2007
Firefox 3 Beta 1 is a developer preview release of Mozilla's next generation Firefox browser and is being made available for testing purposes only.
These beta releases are targeted to Web developers and our testing community to gain feedback before advancing to the next stage in the release process. The final version of Firefox 3 will be released when we qualify the product as fully ready for our users. Users of the latest released version of Firefox should not expect their add-ons to work properly with this beta.
Much of the work leading up to this first beta has been around developing the infrastructure to support a bunch of exciting new features. With this first beta, you'll get a taste of what's coming in Firefox 3, but there's still more to come, and much of what you'll see is still a bit rough around the edges.
Please see below for an extensive list of features and enhancements found in Firefox 3 Beta 1, as well as known issues and frequently asked questions.
As always, we appreciate your feedback either through this feedback form or by filing a bug in Bugzilla.
mas info en
http://www.mozilla.com/en-US/firefox/3.0b1/releasenotes/
fuente:
http://www.mozilla.com/en-US/firefox/3.0b1/releasenotes/
por lo que he leido creo que esta disponible la beta.