It has died down almost completely by now though, thanks to whatsapp, skype and hangouts. I still log on with pidgin and there is at least one person in my list that does the same.
I will never forget my ICQ number, it is burned into my brain forever.
I don't have a need for Whatsapp - although I hear it's super popular outside of the US.
Now I mainly use Google Hangouts, but I always feel like it's lacking and isn't as nice as Skype or other alternatives (for both messaging and video).