After recovering from my myopia surgery, I started to play with the long ago requested synchronous notification support in Npgsql. With it, you will be able to receive notifications from Postgresql server as soon as they are posted.
Right now it can handle correctly the notifications, but I'm having some problems when sync'ing the notification thread. This notification thread will be checking for notifications from server with Socket.Poll calls.
As soon as I got this sync problem done, I will commit it to cvs. Stay tunned.