Earlier this summer I received an unexpected bonus so I used the extra money to to buy my wife a Kindle. She's been really wanting one for a while. She reads a lot and figured this would be a way she could still own lots of books without having to fill our house to the brim (we're half-way there already).
So far we've had a very positive experience with the Kindle. There was only one negative, which was resolved very quickly. About two weeks after getting it the screen stopped refreshing in one corner. All it took was one call to customer support. I didn't even have to wait on hold before talking to a real person!!! They had a replacement Kindle sent right out. I had it in my hands two days after my call.
Anyway, if these things get a little cheaper and text book publishers support them they will have a wide application in education. Every Kindle comes with free access to Sprint's wireless network. This could allow for textbook corrections to be made instantaneously to the copy the students are using. If publishers kept the price down on digital copies of the book everyone would be happy. Students (or schools) wouldn't have to pay as much and there'd be no way to sell used books, which cuts into the publisher's bottom line.
Justifying the price - Right now the Kindle sells for $359. Which is a little steep. However, the free cellular web access makes up for it. In the "Experimental" menu on the Kindle is a web browser. It already has a bookmark for Wikipedia and you can surf most sites, including Bloglines. If you're in the browser and hit Alt-1 it will use the cell towers to triangulate your approximate position; Alt-2 will show gas stations near by, Alt-3 for resturants, Alt-5 for a nearby keyword.
That said, this device is really for reading, not surfing. So, don't expect it to replace a real web browser, but it's great for sites that you spend some time on (news, blogs, ect). If you already have a Kindle you should go to FeedBooks. There you can download a guide to thousands of free books. You download the guide and at any time in the future you simply select a book and it will download right to you Kindle. I think I may have to find more extra cash so I can have one of my own. My wife doesn't like to share ;)