BTW, for those of you with reconnection probles after the last security fix, Airport 3.3.1 is out on versiontracker (not seen it in sw-update so far) Allegedly, it fixes the reconnection problem:
Product Description:
This software update provides improved AirPort wireless networking software, and is recommended for all users with an AirPort Extreme enabled computer or an AirPort Extreme base station.
What's new in this version:
AirPort Update improves reliability of AirPort connections when changing network locations. The update is recommended for all users with an AirPort Extreme and AirPort enabled computer or an AirPort Extreme base station.
Product Requirements:
Mac OS X 10.3 or higher