Apple is seeding a seventh beta of OS X 10.8.5 to developers. The code, listed as build 12F30,
continues a weekly beta update cycle. Apple lists no known issues, and is still asking developers to focus testing on Wi-Fi, graphics, wake-from-sleep functions, PDF viewing and accessibility, and finally mobile device management.
Given how far v10.8.5 is into development, the final release should arrive within just a few weeks. It will likely be the last major update for Mountain Lion, since OS X 10.9 -- better known as Mavericks -- is due to launch sometime this fall.