One vendor, Entourage Systems, caught my eye with something extra at the Consumer Electronics Show. Their Edge e-reader is dubbed a "dualbook" with two screens that are bonded together with a folding hinge. One side is a traditional book viewing page. The other side can be used like a tablet with access to any network accessible information.
Wi-Fi and internet access make the use of eBooks possible for large volumes such as tax manuals, audit manuals, regulatory information and so much more.
http://www.entourageedge.com/entourage-edge.html