The Empire Strikes Back
Taking the Google example, Google is already working desperately to capture all of the shared human experience data and to work it into their index in a usable form. That is what their attempts, though less than pretty, at presenting real-time search have been all about.
Sharing data between people by creating Buzz for Gmail users was headed in exactly the same direction. And Google Analytics together with personalization have both been collating human behavior data for quite some time. Launching Android as an open source vehicle was about taking facilitating share in that vitally important mobile phone access zone.
So, in fact, the "crawler+data organization (index)+algorithm+ search ranking" pattern of search we understand today has to disappear and be replaced with "human behavior logging+data organization (index)+algorithm+ranking" to produce the right result. Google could actually be its own Google Killer as they, for one, are well placed to do this.