I have… my SMP is connected to my HD TV and to my Netgear router. My WD HDD is connected to the back USB port of the SMP. I followed the instructions in the User Manual, under "Moving Files Between the Media Player and a Windows Computer (pg 32). I had to download the WD Link tool from http://products/wdc/com/WDTVLiveG3. Follow the steps to map the correct drive.
Now I can load files through my laptop directly into the HDD wirelessly, and they show up in my Videos. Please disregard if none of this is applicable.