Martin’s official Announcement: http://moodle.org/mod/forum/discuss.php?d=162906
I know it’s taken a long time, it’s been a rough and rocky road. A huge thank you must go out to all the developers, testers, supporters, teachers, trainers, administrators, artists, friends, researchers and students who have contributed to this release. Special thanks to our Moodle Partners for providing most of the funding.
The scope was rather ambitious, with hundreds of refactorings and new features. The release notes have most of the details, but we’ll be continuing to present news about Moodle 2.0 here on moodle.org (and elsewhere) over the next few months.
Download it: http://download.moodle.org/
Release notes: http://docs.moodle.org/en/Moodle_2.0_release_notes