Time Capsule comes with AirPort Utility 5.3, while the latest version that comes with Mac OS X 10.5.2 is AirPort Utility 5.2.2.
Apple most likely will bring AirPort Utility to the same version on the next Leopard update.
Apple AirPort Utility is also available for Windows XP/Vista. (screenshots coming soon)
UPDATE:
I would love to post the AirPort Utility 5.3 installer here, but I don’t want to be served with Cease & Desist letter by Apple.
Airport Utility for Windows
Has anyone tried setting up an AEBS using the Airport Utility 5.3? I’m curious if it affects USB drive / AirDisk stability.