I just pushed a patch to comm-central landing about:support in the tree. If all goes well, it’ll be part of Thunderbird 3.3 alpha 2. The extension will remain available to Thunderbird 3.1 users, and I’ll shortly release an update hard-disabling it on Thunderbird 3.3 alpha 2 and above.
It’s been a great experience driving the project through to graduation. Using the Firefox version of about:support as a base, we looked at what other data’s needed for effective Thunderbird support, and how best to present it to the user while keeping privacy in mind. The model of rapidly iterating on new features by developing them as extensions is a great one.