It is quite interesting that, in this age of Cloud, OTA, and wireless, the only way (without changing to a warranty-unfriendly kernal) to get files from your home server to your HP Tablet is by plugging a cable into your PC and dragging them down a USB wire!
Here is an idea for you developers, because I'm sure you have time on your hands (kidding):
In a similar fashion to Kalemsoft media player, have a "streamer" application on the NAS/server that can stream the files to the touchpad. Not quite NAS mapping, but, whatever works? A large buffer and good MD5 checking for corruption would be desirable.
I Know that you'd have to write it so that it could run on a number of platforms, Linux, WinOS, and the little embedded NAS OSes, but what would life be without a challenge!!!
Or else we could just use the 50gb online storage that you get with every new Touchpad!