Noticed in a tweet from Tim O'Reilly quoting a message from Tim Berners-Lee regarding possibly 'the next big jump in capability' - see this article by Nova Spivack about a different kind of knowledge engine Wolfram Alpha
Wolfram Alpha is like plugging into a vast electronic brain. It provides extremely impressive and thorough answers to a wide range of questions asked in many different ways, and it computes answers, it doesn't merely look them up in a big database.
In this respect it is vastly smarter than (and different from) Google. Google simply retrieves documents based on keyword searches. Google doesn't understand the question or the answer, and doesn't compute answers based on models of various fields of human knowledge.
Presumably if this takes off it will once again change the ways in which we obtain and process information. Just as we got used to searching, maybe now we will have to learn the skill of questioning...