If you run networksetup and do a -listallhardwareports in OS X Snow Leopard, you’ll see that the Hardware Port: for en0 (on an MBA at least, but you should get the point even if it’s a MacPro) is AirPort. If you run the same command in Lion, you’ll notice the the hardware port is now Wi-Fi.
This change cascades to any commands like -listpreferredwirelessnetworks where the hardware port might get called on. For most of my scripts for assigning AirPort networks, etc I was able to mostly just find-and-replace AirPort for Wi-Fi, provided I didn’t use AirPort anywhere else (e.g.$AirPort, etc).
