Beta builds of Thunderbird 2.0.0.12 are now available for testing.
You can get the builds at: http://ftp.mozilla.org/pub/mozilla.org/thunderbird/nightly/2.0.0.12-candidates/rc1/
If you have previously downloaded a beta version of Thunderbird
2.0.0.x or
have manually set your copy to be using the "beta" release channel for
updates, you can update yourself to Thunderbird 2.0.0.12 by selecting
"Tools > Check for Updates".
The status for Thunderbird 2.0.0.12 can be found here: http://wiki.mozilla.org/Releases/Thunderbird_2.0.0.12
If you see any issues with this build of Thunderbird 2.0.0.12, please
report them in Hendrix (http://feedback.mozilla.org/) or by filing a
bug in bugzilla.
Thanks!
-Sam