Apple has released two new versions of its AirPort Utility software: version 5.6 and version 6.0. The former is merely a minor update that aims to resolve an issue with network passwords stored in the Keychain, while the latter is a complete redesign of the software to match its iOS counterpart. The reason behind the release of both versions is that AirPort Utility 5.6 is able to support older 802.11g-only base stations, while the more advanced 6.0 version is not.
AirPort Utility 6.0 will definitely be more highly favored among novice users with supported hardware, as the interface has been significantly updated to offer the simplicity of the iOS version of the software. However, more advanced users may still choose to stick with version 5.6, even with a supported base station. Unfamiliarity with the new user interface in AirPort Utility 6.0 and lack of some advanced features—including the inability to use the app while performing a firmware update on a base station—are reasons aside from hardware incompatibility that may convince users to stick with the “older” and more familiar AirPort Utility version.
Regardless of your choice, whether voluntary or not, both AirPort Utility 5.6 and 6.0 are available now via Software Update and Apple’s support documents for each version.