Apple has taken the wraps off OS X 10.8.3, adding Windows 8 support to Boot Camp and the option to use 3TB+ hard drives with its dual-boot solution. The update also adds the ability to redeem gift cards for the Mac App Store via your Mac's built-in camera, and some bug fixes and performance enhancements, particularly for Safari.
The most notable options are full support for booting Windows 8 using Boot Camp and support for large hard drives once you're booted into Windows, both especially useful for those of us who use multiple OSes on our Mac hardware. The option to redeem iTunes gift cards using your webcam isn't entirely new -- it was introduced in iTunes 11 back in November -- but the update now allows you to redeem iTunes gift cards for the Mac App Store as well.
To grab the update, run Software Update on your OS X system (Apple Menu > Software Update) or grab it from the links below. You can read more about the update at Apple's KnowledgeBase here.