Apple today seeded a fourth beta of OS X 10.10.2 Yosemite to developers, nearly four weeks after the previous beta release. The interval between seeds was slightly longer than usual for recent updates, presumably due to the holiday pause.
Apple continues to ask developers to focus their testing on Wi-Fi, Mail, and VoiceOver. Wi-Fi in particular has been an issue for some OS X Yosemite users since the operating system's October launch, and OS X 10.10.1 released in November failed to resolve all of those problems.
Article Link: Apple Seeds OS X Yosemite 10.10.2 Build 14C94b to Developers