It's easy to get wrapped up in the recent slew of updates from Apple, so let's make this one simple: Got an AirPort Express Base Station, AirPort Extreme Base Station, or Time Capsule? Then this update is for you!
Released on Wednesday, the AirPort Utility 5.4.2 update provides a number of fixes, including an issue that kept AirPort Utility from reading certain AirPort wireless device configurations, and a bug that prevented the software from downloading firmware for the devices.
Apple also added the ability for AirPort Utility to show all wireless passwords in the "Equivalent Network Password" sheet. So, if you meet the standards I specified above (AirPort or Time Capsule ownage), head over to Apple's support page or fire up Software Update and download away.