Less than a week after seeding the initial build of OS X Mountain Lion 10.8.1 (build 12B13), Apple has followed up with a new build to developers. The beta, coming in at build number 12B17, has no known issues. Apple asks developers to focus on Active Directory, iCal, Microsoft Exchange in Mail, PAC proxies in Safari, SMB, USB, and WiFi and audio when connected to an Apple Thunderbolt Display.
10.X.1 OS X updates are usually maintenance updates released soon after the initial 10.X.0 release. The short amount of time between developer beta releases, and the small amount of builds between the earlier release and today’s release should point to that. However, the release notes are yet to be included in 10.8.1 seeds. (as shown above).
Earlier this week, Apple seeded a new beta of 10.7.5, a maintenance release for OS X Lion.