mozilla-thunderbird 1.0.2-2.sarge1.0.8a has been uploaded to the security buildds. It addresses the same issues recently fixed in DSA-1118 for mozilla and DSA-1120 for mozilla-firefox.
I don’t expect hard regressions, but if you find any, please let me know. Otherwise, this package will enter stable-security soon.
You can obtain this build from:
http://people.debian.org/~asac/security/