Not sure why anyone would think that the concept of chatrooms is dead online. Any forums for online chat which I've ever participated in online are not only still there but have more people in them now than they ever did at any point in time in the past. One good case in point is IRC, which is funny because despite it being extremely old and the protocols and software that implement it both on the client and server side, and all the addon technologies people use with it (services, bots, etc.) - many people claim IRC is dead. What makes this funny is that what they're really communicating is that they wish it was dead or perhaps just think it should be dead and are baffled by the fact that there are more people using it now than there ever was and it continues to grow despite their bafflement over it (probably from not using it themselves).

Log on to the Freenode network for example and visit any channel and in the majority of cases there are more people present than ever before. All this while many out there claim "IRC is dead". :) I'm not defending IRC nor tooting its horn mind you, but I do find it funny that people say things are dead simply because they do not use them or dislike them or have an opinion that the given thing is obsolete and people shouldn't use it anymore or similar when actual statistics for the given thing indicate very much the opposite is the actual case of what people are doing. :)

IRC is dead! Long live IRC! :)