In a private email sent to Mozilla employees today, Mozilla shared that on Monday they will be announcing their plans to restructure Thunderbird. Mozilla Thunderbird isn't being killed, but they will basically be making it more community-based with Mozilla employees being re-tasked to other projects.
Mozilla decided that rather than continuing with the Thunderbird e-mail client in its current manner, they can do more good by focusing upon Firefox, their mobile efforts, and the Boot 2 Gecko / Firefox OS.
What they intend to do is "adapt the Thunderbird release and governance model in a way that allows both ongoing security and stability maintenance, as well as community-driven innovation and development for the product. This will mean an eventual shift in how we staff Thunderbird at Mozilla Corporation – we are still working out details, but some people will likely end up on other Mozilla projects."
Mozilla's final plans for Thunderbird will be decided in September. With Thunderbird being one of the few good Linux e-mail clients out there, this is unfortunate news.
More information to be shared next week.