Fedora 7 includes a new module named asus-laptop which replaces the old module asus_acpi.
The led control file for the mail led is now
( 0 -> off, nonzero -> on)
In that way you can "link" it to what is called a "trigger", e.g. something which is generating events to switch on and off the led.
echo heartbeat > /sys/class/leds/asus:mail/trigger
mac80211 wireless devices have triggers for tx and rx too
(to see what are available, just cat /sys/class/leds/asus:mail/trigger )
you can still switch on/off wireless and bluetooth
Note that "wlan" just control the led, though "bluetooth" actually detach the power from the internal usb controller.
Hope this helps