Apple has released a new OS X 10.10.4 beta to developers and AppleSeed testers.
This release clocks in at OS X 10.10.4 build 14E36b. As with previous beta releases, details on what this one fixes are light, with Apple saying that the update "improves the stability, compatibility, and security of your Mac."
Developers and AppleSeed testers alike can pick up the latest update from the Updates section of the Mac App Store. Developers also have the option of grabbing the new build from the Apple Developer Center.