Torbutton 1.4.1 has been released at: https://www.torproject.org/torbutton/
We've updated the experimental Tor Browser Bundles to Firefox 6 and all users are strongly encouraged to upgrade, as Firefox 6 fixes some serious security issues present in Firefox
The stable Tor Browser Bundle for Windows and the beta Firefox 3.6 Tor Browser Bundles for Linux and OS X have been updated to Firefox 3.6.20.
Updated 06/16/2011: Break off window.name into its own linkability issue. While ultimately it should be handled identically to the referer, that was not clear in the original text.
Tor 0.2.2.25-alpha is out and there are the usual packaging updates.
In a random bar about two years ago, a Google Chrome developer asked me why Torbutton didn't just launch a new, clean Firefox profile/instance to deal with the tremendous number of state separation
We now have Firefox 4 bundles available for GNU/Linux. If you encounter any problems with these, please let us know.
UPDATE: there were some issues with the first set of bundles which have been fixed. I've updated the links below.
All of the Tor Browser Bundles have been updated with Firefox 3.6.16 and the alpha bundles for Mac OS X and Linux have also been updated to use Libevent 2, as well as a number of extension updates.
All of the Tor Browser Bundles have been updated with Firefox 3.6.15 and the alpha bundles for Mac OS X and Linux have also been updated with Tor 0.2.2.23-alpha.