The package simply uses /dev/led to set lights on/off , if other systems have led support in freebsd then in theory they should work too ...
APU boards aren't supported in freebsd 8.4 for LED, but are in 10.x , so it should be possible to support them also.
There is some code specific to alix and to wrap already for using the reset button (this needs to include APU boards now also), and showing systems temperature and fan speed only works on some system boards too, so I don't have an objection to adding something like this. Incidentally , using the reset button on wrap/alix causes the leds to flash 5 times to indicate it is resetting.
However i'm not sure if using it as an alternative to NIC activity lights is the right thing to do , it might be more useful to indicate forwarded packets on one LED, and CPU utilisation on another etc