5 years from now, people won't go to Amazon to search for millions of books, or Netflix to search for millions of movies, or iTunes Store to search for millions of songs; they will just go to Google to search for anything, and Google will present the content, hosted elsewhere, in a standardized fashion- a search engine. Perhaps later they will add cool community review and ratings features like eBay, Amazon, and iTunes.
[Thanks to my buddy Kai Dupe for the heads-up on this.]