Sometimes there's not a whole lot of Mac news, but Mountain Lion has provided ample amounts for quite a while yet. It's fantastic, just like how Apple are providing local services to those who don't use Gmail or Exchange, or any of those kinds of messaging and email platforms. Chinese customers running the Mountain Lion beta can select localised services for things such as search, giving them a better experience. The Messages beta, doesn't require a developer account in order to try out, and it means ordinary folk such as you and I can have a go at Messages on the Mac. With the Messages beta, not only can your Mac send iMessage messages to iOS devices, but you can also do file transfers. Ars Technica goes on to answer a few other questions that might come up when you're giving it a thorough run-through.
Mountain Lion introduces Gatekeeper, a piece of software that serves as a compromise to App Store sandboxing — or so say Panic, who have a few more words to say on the topic.
Mountain Lion also introduces Notification Center from iOS. There's only really two downsides: only apps in the App Store will have access to the Notification Center, and we kinda already have the very excellent Growl for notifications on OS X.