Although OS X Mountain Lion has been just recently released, Apple today seeded to registered developers a new build of OS X Lion, version 10.7.5. This new seed has a build number of 11G30.
In addition to Lion, Apple also released a second beta of iCloud Control Panel for Windows.
Obviously, no new features are present in this new build, but Apple has asked developers to focus on graphics performance and quality. There are no known issues in this build.