The public beta is available to the first million users who sign up here.
OS X Yosemite has been redesigned and refined with a new look, new apps and new continuity features that make working across your Mac and iOS devices easier.
Installation of the public beta is done through the Mac App Store using a special redemption code. Apple is rumored to be releasing the gold master of Yosemite on October 10th.
Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.