Roar! OS X Lion, we hardly knew you. Apple has announced a new version of Mac OS X that will debut this summer, just a year after Lion. It’s called Mac OS X 10.8 Mountain Lion, and it continues the theme of bringing iOS features “back to the Mac” in a very big way.

Apple has announced the forthcoming Mac OS X 10.8 “Mountain Lion,” available to developers starting today and expected to be released to the public this summer, presumably bringing the Mac in line with the company’s annual iOS update schedule moving forward.

Further extending the “back to the Mac” mantra introduced with OS X Lion, Mountain Lion is bringing more iOS apps to the desktop platform, including Reminders, Notes and Game Center, all of which use iCloud syncing for cross-platform support between the Mac and iOS.

iChat is getting the boot from OS X Mountain Lion in favor of a new Messages app, which extends the traditional instant messaging and video chat features to include iMessage, Apple’s SMS-like text message system introduced with iOS 5. Video chat remains through AIM, or you can launch the FaceTime app instead.

In what will surely be a blow to Growl lovers everywhere, OS X Mountain Lion also introduces Notification Center, a system-level method for popping up notifications on your Mac in a way that’s similar to the one introduced in iOS 5. A new Notifications pane in System Preferences gives users complete control over when and how notifications will appear.

OS X Mountain Lion also introduces Gatekeeper, a new feature aimed at preventing users from installing potentially malicious apps. “Identified developers” -- which can be any Mac developer with a certificate issued by Apple -- and Mac App Store apps are cleared by default, but users can tweak their settings to fit their own scenario.

Much like iOS 5, Twitter is being deeply integrated into OS X Mountain Lion with a new UI element known as Share Sheets -- essentially a pop-up menu actually reminiscent of the Google Android method, which displays a list of potential services you can share an item with. For now, at least, Facebook is still not among them. (Sad trombone.)

iCloud will finally get a lot more useful with Mountain Lion, with a new Setup Assistant and at long last, Documents in the Cloud added to your traditional Open and Save dialog boxes. AirPlay mirroring also comes to the Mac officially, allowing users to beam their display to an Apple TV when a monitor isn’t handy.

Of course, there are plenty of other tweaks and discoveries to be made in the months ahead, before OS X Mountain Lion roars onto the Mac App Store for all to purchase. Speaking of which, Mountain Lion will be a paid upgrade, much like Lion was, although Apple hasn’t been more specific on price or release date quite yet.

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