I'll admit that even though I've had IM accounts for a decade, I rarely if ever signed in. I found the pop-up like nature of the common clients to be far too disruptive and annoying, and I simply preferred e-mail or voice for routine communication. Lately though, I'm finding IM, under the right conditions, to be far more than just a quick a dirty communications tool. I'm figuring out presence.
If I want to communicate with a coworker, what's the first thing I do? Check IM. If they are around, and if they are available, I'll know right away. If they don't show up on IM, they set the 'do-not-disturb' bit and I know they are busy. If they are 'on call' but no near their computer, they set their status to 'Call my cell phone @ nnn-mmm-zzzz'.
I don't see any reason why things other than persons can't have presence. We've got a thousand or so network & server devices that really matter to us. People we provide service to tend to notice when the devices aren't happy. And we've tended to notice that when people that depend on us aren't happy, neither are we. So we like our devices to be happy.
So here's what I want my devices to do. When they are happy, they set their status on IM to Green & 'Happy'. When they are sad, because they don't have enough CPU, memory or bandwidth, or whatever, they set their status to 'Sad', and perhaps even 'Sad, need more CPU.' Now if I'm a person that either manages or depends on these devices, I build myself a buddy list populated with the devices (servers, routers, firewalls) that I care about, and I see right away if they are green & happy, yellow & sad, or red & dead.
My Mac can even make funky noises when my devices transition from happy to sad & back again. So when my devices change status, they can tell me. Nicely