Looks like it’s nearly done. While translations are in progress at Babelzilla, I removed some small bugs in the last week and adapted the extension to work with the upcoming future Versions (Thunderbird 3a and Seamonkey 1.5a) too. So, I’ll wait some days for any response and than the whole thing will be published at addons.mozilla.org. You can download the new preview at virtual_identity-0.4.0pre2-mz+tb.xpi