Well no offense to anyone, but honestly posting is down because there is just not a whole lot of interesting thread topics to post in. There are a lot of poem threads, but as everyone know they are more for reading and responding so there isn't much discussion there. On top of that, AO just has way too many things for members to do so that is why it would seem so empty. Everyone is spread out.
Not to mention there are clans too. I don't know what goes on in there, but having been in one in the past I am not surprised if members spend more time in there.