Moodle HQ recently announced the availability of it’s newest versions of Moodle code, including 2.5.1, 2.4.5, 2.3.8 and 2.2.11. Note that 2.2.11 is the last release in the 2.2 branch; Moodle 2.3 is now slated to receive only security fixes as per Moodle’s release and maintenance schedule. Announcement https://moodle.org/mod/forum/discuss.php?d=232108.
Moodle 2.5.1 brings several new features and changes, including theme simplification, code cleanup, and a new “Latest Badges Block” for course pages.
Check out all of the release notes here: http://docs.moodle.org/dev/Moodle_2.5.1_release_notes.