Late last year (Nov/Dec), I decided to go on the AIB 64 ladder chatroom. I stayed logged on the entire day (for several days). I just logged on, then did other stuff on my computer or just left my computer alone. At the end of the day, there were only 3-5 people who logged on (most probably just logged on and left immediately). Occasionally, there would be the one guy who asks if I want to play (but I'm not paying attention to the chat / am not on the computer, so I don't see his post).
So basically, that ladder is completely dead. If you want, look through the rankings, and check the "last played" date for everyone. You'll see there has been probably only 5 matches or so for January (haven't checked myself, but that's a guess).
Then again, I'd be up for some sort of ranking system... though the only problem is that most people aren't interested... or quit half-way through. The ladder in the competitive events was probably the best ranking system we've ever tried using (at least... since I've been on the 64 boards)... but people got bored of it, and slowly the ladder died.