An update to Lightroom 4.3 is now available.
What’s new in version 4.3
- HiDPI support within the Library and Develop Modules. HiDPI provides support for Retina-enabled Macs.
- Additional raw file support for 19 cameras including the Canon EOS 6D, Nikon D600 and Olympus PEN E-PL5
- Corrections and bug fixes for issues introduced in previous versions of Lightroom.
Open up Lightroom to get the update.
Update: There is also a Camera Raw 7.3 update through your Photoshop Update menu.