Apple just released OS X 10.8.1, maybe your Mac already told you via Notification Center, but Mountain Lion’s first public update is out. The update includes general operating system fixes that improve the stability and compatibility of your Mac. The delta update appears to be less than 8MB is size.
• Resolve an issue that may cause Migration Assistant to unexpectedly quit
• Improve compatibility when connecting to a Microsoft Exchange server in Mail
• Address an issue playing audio through a Thunderbolt display
• Resolve an issue that prevents iMessages from being sent
• Resolve an issue when connecting to SMB servers with long names
• Address an issue that may cause the system to become unresponsive when using Pinyin input
If you still haven’t updated to OS X Mountain Lion, now would be an excellent time since the first ‘bug fix’ update is out. You can download it here via the Mac App Store.
UPDATE: Apple has released the support document for the update with more details.You can find it here.