Apple today seeded the fourth beta of OS X Yosemite to developers and public beta testers



From MacRumors:

Today's beta appears to be nearly identical to the third 10.10.3 beta released last week, but it appears to solve a problem that prevented beta 3 from working with the new 2015 Retina MacBook Pro and MacBook Air. The new beta, build 14D105g, is available for registered developers through the Software Update mechanism in the Mac App Store and through the Mac Dev Center.

  Apple Seeds Fourth OS X 10.10.3 Yosemite Beta to Developers, Public Beta Testers