Apple has seeded latest beta build 12D58 of OS X 10.8.3 to its registered developers via Mac OS Center, which comes with no known issues. Apple has instructed developers to focus over some of the areas of latest OS X 10.8.3 build including AirPlay, AirPort, Game Center, graphics drivers, and Safari.
If you are already over 12D54 build then you can upgrade to the latest build as delta update or download it directly from Apple.