Following the release of the second Developer Preview of Mountain Lion earlier today, Apple has also released a pre-release version of OS X Lion 10.7.4 to developers. Build 11E27 is available now for download in the Mac Dev Center to registered Mac developers. A Server build for 10.7.4 has also been seeded to developers.
The last public version of OS X Lion, 10.7.3, was released on February 1st, adding bug fixes and addressing compatibility issues with Windows file sharing. A “supplemental update” to 10.7.3 was released on March 5th to resolve an issue with Time Machine backups.