Apple Wanders Into Mountain Lion Territory

Apple (Nasdaq: AAPL) let OS X Lion out of its cage just last July, but the company's already started talking up the next version of its operating system, which it'll call "Mountain Lion."

The details and developer preview that Apple has come out with indicate that even more iOS DNA is being mixed into OS X this time around, with more shared features and functions.
One of the most welcome new features for iOS 5 last year was the Notification Center, and a very similar type of notification tool will show up in Mountain Lion. iCloud will have deeper hooks in the OS, allowing users to upload documents. The mobile Notes app will make an appearance on the desktop, and full-screen mirroring will come to Airplay -- though only in 720p with stereo sound.
iChat will become a thing of the past. In its place you'll find Messages, which will support chats with the usual gang of IM platforms as well as iMessage, the chat system used by iOS.
And one new feature called "Gatekeeper" could make OS X even more iOS-ish in a different way -- not with common features, but with a common security philosophy.
iOS operates in what's known as a "walled garden." Unless you go through the process of jailbreaking your iPhone, the only software you can get is stuff that Apple's specifically OKed and placed in the App Store.
With Gatekeeper, your Mac can live inside a walled garden too -- though you do have the choice of whether you want to stay there, no jailbreaking required in order to leave. You can opt to accept only software from the Mac App Store, meaning you never have to worry about weird programs you don't want somehow latching onto the system. Or you can opt to take stuff only from the App Store and in-the-wild developers that Apple has identified as safe. Or opt to accept installations from anywhere if you figure you can take care of yourself. So it's sort of like supermax versus halfway house versus your own home.
This gives users a choice regarding the old liberty vs. security conundrum, but it could foreshadow a much more restricted future for the platform. When the Mac App Store first arrived, there were already suspicions that the company's ultimate goal was to eventually make its store the only way for Macs to get software. Gatekeeper still leaves a choice, but it could also prove to be another way Apple slowly eases its users into an even more closed-off system.