Gamespy may be removing Neverwinter Nights from their service, indefinitely, starting yesterday I believe. http://social.bioware.com/forum/1/topic/199/index/15193845 Is the social site forum with some more information, but they are removing Legacy support for a lot of games. This does not affect your ability to Direct Connect to servers, but as of right now there is no Server List for any server. Hopefully it will return soon though.

For more information, see this post about how to get to the servers.

As LTenhet says, this does not affect your ability to play online.

http://www.gog.com/forum/neverwinter_nights_diamond/gamespy_has_dropped_nwn_server_lists

Getting Gamespy back doesn't sound likely at this point. Fortunately, people are already trying to figure out ways around it. Direct connecting is easy enough (and I guess Favorites and History are still working), but this is a kick in the pants to new players and anyone who used Gamespy to browse around for new places to play.

This is also going to make setting u new servers a royal PITA. Until now the easiest way to see if your router ports were forwarded correctly was to login to gamespy and see if your server was listed. Now you're going to need to call someone off your network and actually have them try to connect. :-\