Similar to OS X Yosemite 10.10.4, which brought with it some bug fixes and removing the problematic Discoveryd process, the new OS X Yosemite 10.10.5 Beta is also a minor update featuring bug fixes, as well as under-the-hood enhancements such as improvements in stability, compatibility, and security of your Mac.
OS X Yosemite 10.10.5 Beta is now available via the Mac Dev Center for registered devs.