Dual-display e-book concept. Makes sense?

Researchers at Maryland and Berkeley Universities developed a prototype dual-face, modular e-book reader that allows readers to fan pages to advance in a book or via trackball. If you’re doing some serious research, the displays separate from one another, allowing one to display in landscape mode while the other runs in portrait.

Hmm. Dual displays :P I really cannot say if they would be practical in real life usage. I mean, this makes sense while reading a book, but two displays? :/