According to people familiar with build 12D43, the software contains no known issues and the focus areas remain unchanged from the last beta seeded earlier this month.
With the previous build, dubbed 12D38, Apple introduced a new beta installation feature that allows participants to download and install new seeds through the Mac App Store. The company explained the option further in the Tuesday's release, saying that users will be alerted via OS X notification when new seeds are available, much like consumer versions of the operating system.
In order for developers to take advantage of the Mac App Store tool, they must download and install the "OS X Software Update Seed Configuration Utility," which grants Software Update access to pre-release builds. Users can also opt out of the Software Update mechanism if they so choose.
Other than the detailed information regarding the seed configuration utility, build 12D43 has no known issues and developers have been tasked with focusing on AirPlay, AirPort, Game Center, Graphics Drivers and Safari.