Looks like the Mozilla Foundation will be re-structuring, & Thunderbird will be getting the boot. Thunderbird's chief developer apparently favors re-casting Thunderbird as a community project:

"Scott explains that this means that Thunderbird would continue to use Mozilla Foundation infrastructure, such as the CVS repository and Bugzilla, and the new company would perform a similar role for Thunderbird as the Mozilla Corporation does for Firefox, developing, releasing and supporting the application."

I just hope that Thunderbird continues to develop on its current track... we've got entirely too much time invested in rolling it out as our main email client here....