For now, things are going to be pretty silly, as everyone is paying attention to it and probably just endorsing for the hell of it. My guess is that PG started with the threshold being really low, meaning that a single endorsement will actually post the comment and that an endorser needs very little karma to give a good comment. As the karma and endorsements required go up, it will become harder and harder for bad posts to actually become viewable.

I really like this way of doing it; it starts off with the default HN and then makes the filter more and more selective.