Apple has seeded a new build of OS X Mavericks 10.9.3 to developers. The new seed, build 13D38, comes less than a week after the previous seed, build 13D33.
Apple is still asking developers to focus on Graphics Drivers, Audio, Mail, Contacts and Calendar sync over USB in iTunes, and Safari.
The new beta is available via the Update tab in the Mac App Store, and via the Mac Dev Center.