Hi jeep. I'm on there a lot, and so are alot of other people. But I guess only at peak times, and even then you might get a burst of conversation and then it will go flat, and then start up again etc. I think 9pm-1am GMT are fairly busy times (but then I live in the UK, so I would expect there is another peak time.
Many people are srawn into other channels, #betagame, #mandi. A dozen trying to keep 4or 5 topics linear can't; it's nice to be able to devolve space into better orderliness while keeping an eye on and praticipating in the other channels.
Well I am in IRC all the time. I'm an idler. Although there is always something to do, considering I am connected to three different networks and countless rooms, including one of my own. So yeah, if you come in and no one is talking, don't leave right away. Stick around - someone'll pipe up eventually.