I've been watching this project for years and trying to get the lead developer to pick it back up. Since the recent facebook privacy scare its been under active development again, and they have just sent their initial newsletter.
Unlike diaspora, Appleseed actually has an extensive and comparatively mature codebase. It looks like the project will soon have its own non-profit foundation, and certainly seems like something worth promoting and supporting.
Their newsletter: http://opensource.appleseedproject.org/newsletter/06-02-2010.html
Accounts on Appleseed are currently by invite only.