7 watts idle is unimpressive out of context

If you have a NAS that is idle most of the time, and want to minimise power consumption, how about an embedded-cpu based WoL generator? Sniff packets destined for the fileserver, which is otherwise in deep sleep, and automagically wake it up when relevant traffic is detected, with the relevant WoL packet. You'd get say <300mA consumption at 3v3, and full performance on wake. It would be transparent to the machines attempting to access the server. If idle power measurement is your criteria, this might be a way forwards?