Your computer will feel like a phone
The most notable change revolves around built-in software that until now has existed only on iPhones and iPads. Apple summed it up in a note about the developer release, saying, "The ninth major release of OS X, Mountain Lion brings great features inspired by iPad and reimagined for the Mac."
For example, iMessage, the instant messaging service that lets iPhone and iPad users communicate exclusively with other iPhone and iPad users will now be supported on the Mac.
In addition, iCloud integration will be deeply integrated into Mountain lion, with users able to log in with their Apple ID and have their cloud-stored content and documents automatically show up on the computer.
Other iOS apps like Reminders, Notes, and Notification Calendar are also built into the latest Mac software, and it's all meant to allow those with a Mac and an iPhone/iPad to have integration between their devices.
Another interesting addition to Mountain Lion is built-in integration with Twitter, so users can go from booting up to tweeting in a matter of minutes. And finally, the other big update is the ability to beam the stuff that's on your screen to an HDTV via a wireless connection with the Apple TV.
Mostly, though, it's about making the Mac brand look as cool and hip as iOS.