Along with the release of Java updates for OS X 10.5 and 10.6 and the firmware updates for the new MacBook Air system to address some possible system hangs, Apple has released updates for Aperture and an accompanying ProKit update for Snow Leopard.
The version 3.1 release of Aperture adds a host of performance and quality enhancements, including library management, face recognition, and small edits like red-eye correction and image straightening. The 357.55MB update is available for OS X 10.5.8 and 10.6.2 or later. Apple recommends it for all Aperture 3 users, but do be sure to fully back up your system and especially your Aperture libraries before updating. The update is available from CNET's Aperture 3.1 download page but should also be available through Software Update.
The second update is to Apple's ProKit framework, which allows the various Pro applications to interact with other supported applications and services. The update specifically addresses issues with browsing iPhoto libraries in Aperture and some other cosmetic interface bugs with Aperture, and is likely pushed out in conjunction with the Aperture 3.1 release to address these problems. In addition to Aperture bugs, the update fixes incorrect numeric parameter displays in Logic Pro and MainStage.
The update is 13.5MB and will require OS X 10.6 or later. It should be available through Software Update for people who have pro applications installed (even if you do not use those specifically addressed by this update), but can also be downloaded from CNET's ProKit 6.0 update Web page.