The WD TV can be placed on a network via an unofficial firmware upgrade available from B-RAD. The souped-up firmware apparently allows one to plug USB ethernet sticks (I’ve had one of those lying around in my desk drawer for years) into the WD TV and mounts its connected drive(s) onto the network — among other additional features.
I haven’t tried this yet. I found out about it from Tobias Schneble, a reader from Germany who emailed me after seeing my article on upgrading the WD TV to the new official firmware from WDC. Tobias tells me there’s a wiki site where detailed instructions are given.
Updated 4/5/09: I modified the post in accordance with the very helpful comment you see below, provided by the fellow who runs the B-RAD website. It turns out that hacking the WD TV to add it to a network and to enable other extra features is as easy as upgrading it with a normal firmware package. That’s great!