OS X 10.8.3 12D61: Seed Fatigue!
Five, six, seven, eight! Who do devs appreciate? Go, Apple! iOS 6.1 is out and it is a fair bet that OS X 10.8.3 will soon be, too. Yes, lady and lad devs OS X 10.8.3 12D61 has been pushed to the Mac coderati with (again) no known issues.
Knowledgeable canines say that little is known about this latest incremental Mountain Lion update beta other than that OS X 10.8.3
12D61 arrives with no known issues and that testing should focus on AirPlay, AirPort, Game Center, Graphics Drivers and Safari — BOILERPLATE.
In addition to that, Safari 6.0.3 and Mail 6.3 are said to be part of the mix, though specific changes and features are only knowable to insiders, which are shellfishly (i.e. no pearls) keeping everything close to the vest.