I think it comes and goes. The problem is that people attach themselves to a certain group of people, eventually some of these people leave or only drop by seldomly, and to the ones that stay, the new people are never as good (not as funny, contraversial, etc....). Tuc and Jackangel suffer heavily from this syndrome, although they seem to have recently let go of the posters of the past and warmed to some of the new ones.
Right now, things are picking up, I'll guess it's becasue it's summerand there are lots of people that have mroe time to be on. Come late September it will probably slow down again, familiar faces will become occasional visitors and some will never return.