IRC has little to do with it, actually. Aside from someone popping in here and there, it's been mostly the same ol regulars. (which by the way I wish would change)
I'd say more than anything it has to do with the fact we've had 13 unique users today. Not that there's anything at all wrong with that. We're a small community, losing a typical amount of lurkers just like any other forum. And there just isn't any new blood to replace them. I mean if I'm not mistaken, I'm still the newest active site member.