Apple has whipped out a preview of the next major version of OS X, and its name is Mountain Lion. This isn’t a “nip and tuck” update like Snow Leopard was for Leopard, though, and it isn’t “making OS X more like iOS.” This is a major feature release that brings a lot of good core ideas that would be useful in any OS, and which simply debuted in iOS first since that’s where all the insane growth is, to the Mac.

Headlining features include: Messages (you can download a beta today), Twitter integration, AirPlay Mirroring, Notification Center, Reminders (sensing a theme yet?), Notes, Game Center, and new security features called “Gatekeeper” (disabled by default) that let you control what software you install and run on your Mac.

Apple did things a little differently this time around. For one, it announced a new OS in the middle of February, and it gave press unprecedented access and early previews of developer builds. Check out what the Apple web has to say about their time with Mountain Lion so far: