Neither IM nor Facebook is dying. Email's not dying either, but your countersuggestions are absurd.

Didn't say Facebook is dying.

Traditional IM is suffering, IMO: Twitter, Social networks and Skype ate its users. And, paradoxically, even Email.

Maybe it's just me who use them less and less? No idea.

Huh! If you don't count Skype as IM then I agree with you. That's my primary IM at the moment. But isn't that IM?

I always thought it's more of a phone thingy?

Well, it handles text/audio/video chats. But text chatting is still a big part of it: Right now I'm using it for group work, because it has a great filesharing system. It's very flexible, but I think it still counts under the instant messaging umbrella.