Apple has just seeded a second beta release of OS X 10.9.2 to developers. The new build is labeled as version 13C39, and can be downloaded via Software Update in the Mac App Store for users running the first beta, and also from Apple’s developer portal.
The first 10.9.2 seed added enhancements to both the Messages and FaceTime applications, allowing for FaceTime Audio calls.
A feature added this go-round is the ability to block people on FaceTime and iMessage. The OS X blocking syncs with your blocked contacts in iOS 7.