Google's mission is to organize the world's information, but much of that information isn't yet online. Google Print aims to get it there by putting book content where you can find it most easily – right in your Google search results.
Good enough. The problem is, I haven't yet come across a book whose entire content is online. The maximum amount I have been able to access for any one book is about 15 pages.
So what's the point? Is this in fact only an elaborate way of getting users to buy the book, as the numerous "buy this book from" links would suggest? There is in fact supposed to be a "find it in a library" link, but it doesn't appear on any pages that I have seen.
At this point, Google Print (and I know it's in the beta stage) is the print equivalent of a peep show: "Try these free samples! Get hooked and buy the rest!" They're going to have to lift some limitations on presenting full content, or else the tool will be more frustrating than helpful.