Google’s branching out to search more than just Web sites. The Google Print FAQ explains that they’re experimenting with “publications” (what they mean by that, we don’t know, but it looks to be primarily books). They are, undoubtedly, using this to compete with Amazon’s full-text book search efforts, and become the one-stop-shop for searching everything.
They’ve already indexed thousands of books, including some popular ones. When you click on a book title, you’ll see information about the book: number of pages, excerpt, publication date, and its ISBN number. You even have the option to buy it at a few retailers (I could see Google add a referral code to those links to get them a bit of kick back — I know I would).
Interesting feature? Yes, indeed. With Google indexing IRC channels already, it won’t be long before they’ll be indexing everything. Now if they could just create a unified interfaces for all of their indexes.