If you bought one of the new 802.11n base stations it includes a CD installer for "Airport Utility" that works on Intel and other Macs and PCs as the only way to configure the new 802.11n access points. Airport Utility can also configure Airport Extreme and Airport Express Base Stations but Airport Utility cannot configure Graphite or Snow models. The firmware included is not different for Airport Extreme Base Stations (5.7) or Airport Express (6.3). Only if you have the new utility installed will this update be necessary or available in Software Update.

This update changes the old Airport Admin Utility's name to "AirPort Admin Utility for Graphite and Snow" and the version number changes from 4.2.3 to 4.2.5. The old utility will also still configure Extreme and Express Base Stations.

The standalone installer requires a restart but the Software Update version does not. I would not recommend installing the standalone version unless you already have Airport Utility 5.0 installed, not to be confused with Airport Admin Utility!

I like the new interface in Airport Utility and have found no problems with this update except the old utility is behaving like the new one in that base station admin passwords are not being stored properly in the keychain even though that check box is checked.