I wonder why Google took so much time to come up with this kind of service. Read more about it at google’s blog. It will be interesting to watch impact of this service on research/publication/tenure in academic circles.
Study the timeline, google first came up with a search tool for different languages, then image search,and after that “froogle” and then after something like nine years since their inception they have come up with “scholar”.
It is quite possible that when Sergey Brin and Larry Page decided to build “google” then they could have thought of doing it for reducing their literature review workload (part of doing a phd). During the process of building up this company they must have forgotten about this (as so often happens with most of the phd scholars, they do everything else but their phd). This tool (scholar) will be of great help to researchers all around the world.