Apple today announced that OS X Mountain Lion, the ninth major release of the world’s most advanced desktop operating system, is available as a download from the Mac App Store. Mountain Lion includes more than 200 innovative new features, such as iCloud integration, the all-new Messages app, Notification Center, system-wide Sharing, Facebook integration, Dictation, AirPlay Mirroring, and Game Center. Mountain Lion is available as an upgrade from Lion or Snow Leopard for $19.99 (US). …