I think the main problem is that, as far as I've come across, most people don't know about eInk - I've yet to have a single person I told about buying my Sony as a grad gift to myself have any idea what I was talking about, and I usually started off with "have you heard of the Kindle?" since I figured they may have seen it on Amazon's homepage.
Up until a couple weeks ago I would have agreed with most of the people - no ebooks for me for class either. I was, and would assume most people, would equate it to reading books off the computer, and that is no fun, especially for a textbook. When I've had professors post online some of the readings I've printed them out - partly for readability and partly for highlighting.
I think if before being surveyed they were shown an example of what the possibility was and the answers would be different. I also think though that the real contender would have to be the Iliad or something that was similar - many people like to scribble notes in theirs and I know I highlight my books like crazy and that is a requirement for me. Actually, I downloaded some of the works I still need to read for my Classical Mythology class (ironically, one of which is the Iliad), but I will be reading and studying them from my textbook - the need to highlight justifies carrying around a 1200 page book.
So, I think that we would prefer ebooks if:
- We knew about eInk and such devices
- The devices had the ability to highlight and mark up
- The device price went down a lot (particularly compared to the current price for those that have the ability to highlight and mark up.)
- It was integrated to the point where we knew we would be able to get all of our books in ebook format to justify our expensive device purchase
- The ebooks were considerably cheaper than the p-books, especially since I doubt we'd get the ability to sell it back for a bit of extra cash, which would make it really annoying.
The ability to search alone would be such a time saver and makes a big difference. It would probably in the long run be as much or more profitable to the textbook industry - as much as they love to make us buy new editions every two years

when we do used books that money is going to the bookstore or the person online we snagged it from, not to them. This way they can directly make us each buy the book from them. It could potentially have a sell back feature - say you buy it with a timed DRM for the full price, and then at the end of the term you can either keep the book and then they can remove the timed DRM part (or you redownload it or however the technology would have to work) and if not you can get a partial refund and the book dissappears.
Anyway, the potential is there, I just think most of us don't know about it and it isn't worked into the system. Considering my school is on trimesters and you can pay up to $1800 a year in books depending on your major, if the books were actually cheaper than the paper versions it would sell like mad.