Imagine how much easier it will be if my wife and I, who share calendars on Google, can use some kind of service that would propose a few flights for our family to some desired destination at some free cross section of our time—the move from Internet calendars and other identity-rich measures (whether of the Google, Yahoo or other variety) to integration with already existing web services we all use (for everything from travel and budget planning to various other purchases, projects and plans) should be a relatively trivial matter.
Another scenario—I'm looking for a house. My calendar is on the web. Some service can arrange house seeing expeditions for me and reserve time on my calendar.
This does not seem to be a tremendously difficult mathematical problem, and it doesn't involve much AI.
So, why don't we have these types of services yet. Lack of proper integration?
This type of integration simply allows to deploy other dimensions of search and constraint satisfaction technology—any search or technology that reduces transaction costs and brings real convenience to us. There is not really much else to it!