According to people familiar with Apple's seed notes for the release, focus areas for the beta include iCloud Document Storage, Address Book, iCal, Mail, Spotlight and Safari. The build was reportedly seeded with no known issues.
The combo update is a 1.25GB download, while the delta version weighs 986.68MB.
Developer releases of Mac OS X 10.7.3 have come fairly regularly in recent weeks, with the previous build, labeled 11D33, arriving on Dec. 15. Apple began testing the update in mid-November.
Earlier this month, beta drivers for AMD's next-generation graphics cards were discovered in a beta build of the update. AMD's new cards, which are expected to arrive on the market in the first quarter of 2012, could power a future iteration of the Mac Pro, though Apple is believed to be debating whether to continue making its full-sized workstation line.
Apple released OS X 10.7.2 in October, adding iCloud support to the desktop OS.