Once in awhile a student or professor asks about Google Scholar, wondering how useful it is and so forth. Maybe the best answer is that it is still early days yet for Google Scholar and that time will tell. (If you don't know what it is, Google Scholar is a Google search site that focuses on articles, books...)
One basic factor here is the availability of the actual articles, the full text, that many of you want to be able to find. There isn't nearly as much of that in Google Scholar as there is in, say, Academic Search. Why not? Because publishers don't care to post their literature in free sites; they much prefer to sell it to libraries!
Another problem with Google Scholar is that it doesn't do some simple and helpful things, like present results with the most recent first. Academic Search and similar databases libraries offer do this sort of thing as a matter of course.
On the other hand, librarians do understand that when people are presented with a long list of resources, without a lot of information as to which to use, people obviously can find navigating their way around frustrating. It isn't helpful either that each site is different from the one before!
So where will it all lead? There are different opinions, but certainly libraries, and Google, are working to make things as simple and user friendly as they can be!