We're getting very close to the Thunderbird 1.0 release and making our final stability push. If you'd like to help us with this, please download the latest branch nightly Thunderbird build and when you install it be sure to select the "custom" install so you can be sure that the Talkback crash reporting component is enabled.
We've fixed a number of serious stability problems and in order to verify that the crashes are indeed fixed -- and that we haven't introduced any new ones, we need a lot of users testing the latest nightly builds with Talkback enabled.
These builds are quite solid and I use them without fear of losing any of my data (including tens of thousands of local messages in my POP3 account). It's always good practice to have backups of sensitive data (even when running production software) but Thunderbird has been so strong for so long that I don't fret dataloss at all.
So join us as we drive the final miles to Thunderbird 1.0. There's no doubt in my mind that this is an Outlook-killer and we just need to get those magic numbers, "1 dot 0" attached to it so that the rest of the world will feel safe in trying it out. You can help us achieve that 1.0 status by downloading and using these latest nightly builds.