updated 08:23 pm EDT, Mon April 1, 2013
Notes are identical to final 10.8.3 betas
Just two weeks after Apple finally released Mountain Lion OS X 10.8.3 to Mac users, the development cycle on the next minor update, 10.8.4, has begun. Currently only available to AppleSeed testers, the first beta of 10.8.4 will be distributed to registered OS X developers through Software Update soon, and comes with no known issues. Curiously, the release notes on 10.8.4 are the same as the last betas of 10.8.3 -- asking testers to test Wi-Fi, graphics drivers and Safari. The new build, 12E27, is likely focused on bug fixes.
There is no mention of any new changes in the new beta, but 10.8.3 brought some unexpected new features -- an updated Safari and better iTunes integration, along with new drivers for Windows 8 support in Boot Camp -- as well as the usual fixes. Initial reports indicate that 10.8.3 resolved some nagging wake-from-sleep issues for certain Macs with Nvidia video cards, some graphics bugs, Wi-Fi connections on waking and even slightly improved battery life. It also closed some potential security issues and an odd "file:///" crashing bug.
The delta version of 10.8.4 requires a Mac running 10.8.3, however a combo version is available that can be installed on machines with 10.8.0 or later. A timeframe for 10.8.4 has not been revealed, however the previous release took a number of months of testing before it was released to the public, including a record 13 betas.