I have not been terribly interested in e-readers like Kindle because they are simply electronic books. They don't offer much more than the printed version and there isn't much more you can do with them apart from reading text. In addition they are in black and white with no photos or illustrations. There is simply few compelling reasons why I should buy such a limited device.
The iPad and all its competitors have really swept the e-readers away since they do so much more and can offer a reading experience that printed books can't deliver. E-books have to be different from print, they have to offer features you can't get in print and only then will people really start buying them.
He's a recent TED talk by Mike Matas showing a new type of interactive e-book that points the way forward.