While this is a nice effort, why use Google Talk at all for chatting if you're going to do all this effort (per user configuration etc) if you could just use an XMPP client with OTR[1] support, or use an XMPP server you can trust?
So, I guess, it's a bit more than nobody.
I can explain my girlfriend and brother how to enable and configure OTR. I would have a hard time getting them to execute the instructions for this addon.