Apple this morning announced OS X Mountain Lion, the next release of its desktop operating system for its Mac computers. Among the new features debuted by Apple this morning—many of which were based on existing iOS apps, including Notes, Reminders, and Game Center—is AirPlay Mirroring. As the name suggests, the feature will allow users to mirror their Mac’s screen on a HDTV using an Apple TV, making it easy for users to share web…