Apple released the latest beta build of OS X 10.8.3 to developers, dubbed 12D68, as the forthcoming update moves closer to public release. From Apple Insider:

The most recent seed comes one week after the previous build 12D65 was rolled out with a fix for the "F:///" detection bug that would crash a number of OS X apps.

With no known issues, the latest seed is the eleventh such beta pushed out to developers, though Apple has yet to issue a Golden Master that would signal an imminent public release.

As with the past few builds, the latest 12D68 focuses on testing AirPlay, AirPort, Game Center, Graphics Drivers, and Safari.

 Apple releases build 12D68 of OS X 10.8.3 beta