Adobe released the new Lightroom 4.3 and Camera Raw 7.3 release candidates through Adobe Labs, today, giving support for the Retina MacBook Pro displays as well as full support for the Nikon D600 and more!
For those unfamiliar with release candidates, they are pre-release versions of software that aren't fully supported or guaranteed to work perfectly. While they are the most fine-tuned piece of software before the official release (usually with some minor tweaks still needed), it is not recommended to use release candidate software for business-critical work, as there may still be slight bugs to work out. That said, I've never had an issue myself with Adobe's RC software and think the update is great for those with retina displays (myself included). Enjoy!