I was perusing through the work of the HCI and visualization groups at UC Berkeley and found a really interesting paper on new ebook device concepts entitled "Navigation Techniques for Dual-Display E-Book Readers", by Nicholas Chen, François Guimbretière, Morgan Dixon, Cassandra Lewis, Maneesh Agrawala.

In this paper we present our design of a dual-display e-book reader and explore how it can be used to interact with electronic documents. Our design supports embodied interactions like folding, flipping, and fanning for local/lightweight navigation. We also show how mechanisms like Space Filling Thumbnails can use the increased display space to aid global navigation. Lastly, the detachable faces in our design can facilitate inter-document operations and flexible layout of documents in the workspace.

The group has a good video [9,2 MB] describing the concept.

Looking at the video made me realize how relatively trivial it might be to extend Google's Android functionality with a Google Book Search API, permitting Android devices to read, annotate, and manipulate page images and metadata contained in the GBS product (e.g., the bookshelf functionality). This would make sense especially if GBS' in-copyright content is monetized through pay-per-view or licensed access plans. The strategic advantage of this approach - characteristic of the Android platform - is that Google empowers the creation of a wide range of devices but is able to privilege their own content (without locking out anyone else).

That strategy flips Amazon's approach of tying hardware to a repository, and the contest between these approaches would indeed be interesting in the market.