There doesn't seem to be a mailing list I can register on, although the 'New Versions' support forum says "Registered users might receive notification whenever new post is submitted to this forum".
Is there a way of changing the above 'might' to 'will'...? :)
You will receive notification if you opt to watch for changes in the respective topic in the forum.
But I admit it does not work sometime. I'm going to make some changes (the site will be redesigned soon, hopefuly).
You may also register to receive notifocation on sourceforge download server. It is reliable.