I have come to the realization that for non-fiction especially, and I think this was mentioned in the article, adding notes in the margins and being able to quickly navigate back and forth through a print book are big advantages. And retention of what you are reading, as someone here mentioned, does seem noticeable to me and I think there is some debate about it now in schools as students are moving to Chromebooks and iPads.
http://www.scientificamerican.com/ar...with-a-laptop/
http://blogs.discovermagazine.com/cr...nk-of-reading/
One thing I've begun to think about is the amount of information on a page. A six inch screen allows for so little information to consider at one time that I have wondered if considering larger passage at a time might also be of benefit, perhaps a larger screen reader might prove more profitable.
Lately with ebooks I'm becoming a bigger fan of Android apps vs. e-ink ebook reading, after looking at the features in some Android reading apps, font and color and formatting features, e-ink devices seem almost crippled by comparison. Also the highlighting with color choice is an advantage. You get more control and options with Android reading apps. The problem is getting those highlights and notes backed up and saved properly with some apps and devices.
The .lit format did go extinct, so the idea of file types dying out is not unheard of
http://the-digital-reader.com/2011/0...-ebook-format/
I suspect Amazon will kill Mobi at some point. If a company owns a file format, they can kill it at will.
Yet I think Epub will have a long life as an open file type. Perhaps in a perfect world all ebooks would be drm-free plain text files that the reader could format to their own pleasure with options or templates within their e-reading software.