Apple has seeded the second beta of OS X Yosemite 10.10.2 (build 14C78c) to developers. The second seed comes two weeks after the first beta of the update.
The new beta is available both via the “Update” tab in the Mac App Store, and in the Mac Developer Center.
The release notes for the second beta of OS X 10.10.2 asks developers to focus on Wi-Fi. Many users have complained of issues regarding Wi-Fi stability ever since the release of OS X Yosemite back in October.