People familiar with the software update say that a pre-release build of OS X 10.7.4 will be released to a limited number of developers within days. A wider release to all members of the Apple Developer Connection is likely to take place by week's end.
Exactly what enhancements or fixes will be contained in the OS X 10.7.4 update remain unknown. Apple typically releases a number of beta builds to developers for testing before an update to OS X is released to the public.
The previously unannounced update to Lion was mistakenly referenced last week on Apple's official website, following the launch of iPhoto for iOS. The official site noted that the software was compatible with the latest version of iPhoto for Mac, which it said required a system running OS X 10.7.4 or later.
The last update to Lion, OS X 10.7.3, was released to the public in early February. It mainly addressed bugs, but brought a handful of new features like support for new languages, Wi-Fi connectivity fixes and Windows file sharing compatibility.
The forthcoming OS X 10.7.4 is likely to be one of the last updates to Lion before its follow-up, Mountain Lion, becomes publicly available. OS X 10.8 is scheduled to launch this summer on the Mac App Store packing over 100 new features, including Messages, Notes, Reminders, Game Center, Twitter integration, Notification Center, and AirPlay Mirroring.