there are a lot of articles popping up on " Why i left , hate , sucks, and more about facebook"
I just left also after 3 years it was crazy, but a friend called me up and noticed that i was not on it anymore and other friends have noticed also( that was a face book standard comment worrying about nothing loll ) but he told me that out of many friends he has he has block there comments and wall comments and apparently this is becoming very common where if you want to talk to somebody you have to leave a message. I think you can see a rebound happening here and i think facebook is going to need all a our help to keep them going and that is why they are developing these mods to allow our forums and many other scripts to connect to face book , we will just become part of there network. there is also a trend where folks who are signing up are not using there real names like you would at a forum.
here is a good reenactment video on face book
http://www.youtube.com/watch?v=PVA047JAQsk