It's a banner day for updates to all things AirPort. Apple has released version 7.6.3 of its AirPort Base Station and Time Capsule firmware, along with version 6.2 of the AirPort Utility for OS X 10.7.5 and later.
The updated AirPort Base Station and Time Capsule firmware brings with it the ability to extend Guest WiFi on networks featuring multiple Base Station units. It also lets you add WPS-capable WiFi printers and adds support for additional countries. It's compatible with all 802.11n AirPort Extreme, AirPort Express and Time Capsule devices. Apple recommends having AirPort Utility 5.6 or later installed on your computer before performing the firmware update.
Speaking of AirPort Utility, it's been bumped up to version 6.2 to add the necessary settings for configuring the aforementioned Guest WiFi and WPS printer capabilities. Hit Software Update to download both it and the new firmware.
Hat tip to Wheat Williams!