Five features I want from an ebook reader that could be developed with reasonable ease, rather than the ridiculous "it will play movie clips & integrate with Facebook" that some publishers & hardware designers seem to think are important. (And, hey, if you're dying for ebooks with animated scenes, or want to have an ebook club connection through your reader, more power to you... it's just not what I'm looking for in ebooks.)
1) Sort by "most recently viewed." Or more simply coded, a list of "10 most recently viewed ebooks." This would be a great boon for scholars who need to flip back & forth between books. Right now, most reader software sorts by Title or Author, with some readers sorting by Date Loaded and others sorting by folders, tags, and bookmarks--but I don't think any will let you open the book you were reading before this one, without navigating through one of those other methods. Even a simple "open previous book" would be useful; people would be able to switch back and forth between two books, rather than re-navigate to their main reading in order to try a sample of something new.
2) Flip through. Most e-ink can't do this regardless of whether the code gets written; the pages don't turn fast enough. But LCD screens could do this, and anything that can support video could support a flip-through feature: start at the beginning (or any bookmark or chapter break) and scroll or turn *quickly,* 15-25 pages/second, with a halt feature so you can stop at chapter breaks or images or poetry or whatever else catches your eye, the way you can with pbooks.
3) Coded bookmarks. Not just bookmarks, but tagged bookmarks--like color-coded post-it notes. I want to use yellow tags for "quote this" and red ones for "historical details" and blue ones for "point for rebuttal" and green ones for "re-read this section later." Or, in the case of black-and-white readers, symbols could be used for those--a square, a diamond, a dot, a star, whatever. Coded bookmarks would help with both academic research and casual reading, although the casual codes might be "share this with spouse" and "google for more info" and "typo; write to author" and "hot & sexy scene starts here." It'd be an invaluable feature for beta readers; four separate types of bookmarks would make it easy to note "typo/grammar" and "fact-check this" and "inconsistent story detail" and "dialogue needs touchup."
4) Picture fills the screen. I'd love to be able to have any image shown at my choice of "full original size" (if small) or "fills viewing screen", preferably switchable between landscape & portrait. Image support in ebooks is far enough behind physical books (200 dpi max?!) that this could help cover the gap until we get print-quality displays, which I suspect are not happening soon. Or at least, not happening soon & cheap.
5) Open to a random page. Or at least a random chapter. When I pick up a pbook in a store to decide whether to buy it, I don't open to Page 1 & begin reading; I open to somewhere in the middle & see if the prose style catches my attention. Usually, I start at a chapter break (which is easy to spot in a physical book; may or may not be marked in an ebook). When I pick a much-loved pbook off one of my own shelves, I may not start at the beginning; I may flip halfway through to start at "sometime after the abduction but before the plane crash." This is the feature that would allow ebooks to replace/supplement the "bathroom book of trivia" books--two-minute mysteries, collections of aphorisms or quotations or jokes, even newspaper editorial books, which are generally published chronologically but people may not read them that way. It'd also be useful for magazines, especially if combined with the flipthrough option.
ETA: Most of these have been debunked; I didn't do enough research before posting.
"Coded bookmarks" may be the only one actually not available. Thanks for letting me know, folks; I'll try to do more checking next time. (In the meantime, I found out that some of my most-wanted features *are* available, so yay!)