He raises some very good points - paperback books are the size they are not only because they're a comfortable size to fit in the hand but they're also a comfortable size to read in terms of saccadic motion. You don't need to have huge eye movements from the right end of the text to the left upon completing a line, and the entire page is within the central (i.e. 4-5 saccades wide) portion of the vision.

It's why I don't like reading novels on the computer - the screen is too wide. Reading them on the Palm is fine because the screen slightly smaller than a paperback.

I like his concept of a 'reading view', but as qidane pointed out it will have to be tweaked a little for people with non-standard visual requirements. The basic premise of a limited width reading column still remains sound though as the central visual field will remain the same.