...we just had a quality generic .ws domain (related to the real estate industry) sell for $2100 US.
This is the first I've heard of an undeveloped .ws selling for this much. So, I agree with Bob: Don't invest in .ws! But if you already have, then at least now you know that it is possible to make some good sales here. If your domains contain some quality keywords, and are adult-related, they could have some potential.
Good luck!
~Matthew