You could potentially set up your NIC to wake up for directed traffic, but you may find your PC waking up for a lot more than when you want. WOL is more specific and the best thing to use, but it does require something to send the WOL packet. One program you could use to provide this function in an automated way on the PC is DVRMSToolbox.
While the Xbox acting as a WMC extender does send WOL packets; IIRC, some of the other manufacturers’ extenders may not have performed this function.
