Kurt Peters thinks ...
The next big thing will be something we’ve seen developing already, though it is not very common: the breaking of the linear approach to navigating a web site. Until now, moving through a Web site has been a lot like looking through a book, magazine or catalog (which is natural, given how long humans have interacted in that fashion with a vehicle that contains content, i.e., scrolls, books, etc.). But the development of Web 2.0 approaches and technologies breaks that navigation open and allows the Web experience to become something completely different from what we’re all used to. In retail, that means shoppers will be able to view details about a product, compare products, match one product up with another, view reviews, and see what’s in the shopping cart, all without having to toggle back and forth between pages. That will make the experience more interesting and gratifying than what it is today.
The other next big thing: E-commerce everywhere.
From a interesting short interview with him on ATG blog.