Google Scholar is a beta service that is aimed at academics. In their words,
Google Scholar enables you to search specifically for scholarly literature, including peer-reviewed papers, theses, books, preprints, abstracts and technical reports from all broad areas of research. Use Google Scholar to find articles from a wide variety of academic publishers, professional societies, preprint repositories and universities, as well as scholarly articles available across the web.
As Willard McCarty pointed out on Humanist, there is a good interview with Terry Winograd on ACM: Ubiquity with the tile, Talking with Terry Winograd Winograd is taking a sabbatical at Google and has this to say about Google,
What surprised me, which Google was part of, is that superficial search techniques over large bodies of stuff could get you what you wanted. I grew up in the AI tradition, where you have a complete conceptual model, and the information retrieval tradition, where you have complex vectors of key terms and Boolean queries. The idea that you can index billions of pages and look for a word and get what you want is quite a trick. To put it in more abstract terms, it’s the power of using simple techniques over very large numbers versus doing carefully constructed systematic analysis.