It seems awfully fast for Google to have pulled the plug on Wave.
It was only first launched in May 09 and out of beta May 2010. Most non-techies haven't even heard of it yet. New communication mediums don't take off overnight, they'd have been looking at decades for a reasonable level of adoption. If they'd pulled the plug on the world wide web that fast it would have barely been noticed by most people.
I liked the look of Wave, though I couldn't see how I would use it. Collaboration only really seems to work in a work environment, how many times have you needed to edit a document at the same time as your parents?
Likewise instant typing update, who needs it? I like the asynchronous nature of email, it lets me respond in my own time and likewise the people I contact. I don't use IM at home as it's too disruptive (if someone IMs me I feel I need to respond right now, I don't with email).
Some of the other features were good. Playback, for example, and much of the drag and drop, but most people have no need to edit things simultaneously. I suspect many of the component technology will make its way into other applications though.