It's only been seven months since Apple launched Mac OS 10.7 Lion, but the company isn't sitting still: it just announced the developer preview of OS X 10.8 Mountain Lion, a tweaked and enhanced new version of the operating system that includes major new features like Notification Center, AirPlay mirroring, and iMessage. Yes, those are all headline iOS features as well; Mountain Lion continues Apple's cycle of using the iPhone and iPad to influence Mac development and vice versa. And note the name change — Apple's dropping the "Mac" and simply calling it OS X Mountain Lion.

Mountain Lion also represents a dramatic speedup in the pace of OS X updates: Apple says it'll be issuing yearly updates from now on. That's partially to match the breakneck pace of iOS development, but also to capitalize on the growing popularity of the Mac in general — Mac sales have outgrown the general PC market for something like six years now, and Apple says it's investing heavily in the platform to build on that trend.