Apple has released an update to Aperture, bringing the program to version 3.0.3. The 69.4MB update should be available through Software Update for those who have Aperture installed, but also can be downloaded at the update's webpage. The update addresses issues with repairing and rebuilding libraries, working with GPS track files, managing referenced files, Apple's face detection, managing adjustments and RAW fine tuning presets, and duplicating smart albums.
You can read more about this update in a recent in-depth article by CNET's Stephen Shankland. The update requires OS X 10.5.8, or OS X 10.6.2 or later.