In 2009 I was completely blown away by Google Wave.
I was particularly interested in the new ways of collaborating and communicating. Some real time features, that are available in Google Wave, I never saw before on other platforms.
Recently I heard that the development was stopped and Google would only continue using it their own products but as a platform.
It is a pity but apparently people were not ready for these new ways of communication. I still hope to see features like side-by-side typing appearing future products. May-be they get accepted when released at a slower pace. On the other hand I still need to convince my parents to use text messaging and chat. For some people adapting to new ways of communicating will always be hard.