I don't think its 50/50.
There are plenty of forum members that don't subscribe to any of the Abrahamic traditions but seem sure there is an omnipotent entity.
I actually think it takes a lot of strength to discard the notion of god's, contrary to popular opinion. I also don't think most atheists are immoral or even amoral which is also counter to the prevailing thoughts around here.
Jewish atheism is not the same thing either, this stems from a completely different view of god where 'god' is not so much an all powerful entity as it is the will of the Jewish people themselves. I've written about this aspect of Jewish atheism before.
Contrary to popular opinion, only Jews think that they can be atheists, non-Jewish atheists are a threat to Jewish ideology and thus they treat them with a profound contempt that is worse than the mere ridicule reserved for Christians.
Just clearing the air preemptively before all the chest nuts get paraded out...