Check out Google scholar, the Beta is online now. It allows 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.
I would be very interested to see how libraries could utilise this. Will look at giving it a good workout and review in a day or two.
In the meantime,The Chronicle of Higher Ed, Searchenginewatch and ResourceShelf have reviews.
--------