Apple® today released a developer preview of Mac OS® X Lion, which takes some of the best ideas from iPad™ and brings them back to the Mac® for the eighth major release of the world’s most advanced operating system. Lion features Mission Control, an innovative new view of everything running on your Mac; Launchpad, a new home for all your Mac apps; full screen apps that use the entire Mac display; and new Multi-Touch™ gestures. Lion also includes the Mac App Store℠, the best place to discover, install and automatically update Mac apps. The Lion preview is available to Mac Developer Program members through the Mac App Store today, and the final version of Lion will ship to customers this summer.
Apple - Press Info - Apple Releases Developer Preview of Mac OS X Lion