According to release notes, the update includes "improved AirPort wireless networking software, and is recommended for all users with an AirPort Extreme and AirPort enabled computer or an AirPort Extreme or an AirPort Express base station."
Apple also released Monday AirPort Express 6.1 firmware. The biggest new feature in the update is support for the Keyspan Express Remote, a device which allows you to control iTunes, and now AirTunes, with a wireless remote (US$59.95 from the Apple Store).
Other changes include:
- USB printer renaming
- WPA security on WDS networks
- Improved reliability on WDS networks
- Ability to disable the AirPort wireless interface
- Ability to disable the ethernet interface
- AirTunes reliability through AirPort Express
- Issues regarding FTP, RTSP, IPSec, TCP, UDP, and other IP protocols such as DNS and PPPoE
- Other performance enhancements and bug fixes
The AirPort 4.1 update weighs in 13.6MB, and the AirPort Express 6.1 firmware update is 2.4MB.