As electronics get smaller and thinner, it almost seems as if they are being made to be used with a case. Before, the case was a bulky way to protect your phone, ebook reader, or whatever you were using, but now I find my iPhone and iPad are easier to hold with cases on. It gives a bit of individuality, some protection, and a better ergonomic feel when the device plus the case can be made to feel right in my hands. I no longer have to compromise between the device I want and the device that feels right. I can get the device I want, find the right case for it, and turn it both into the device I want and the device that feels right.
My nook, on the other hand, is both the device I want and the device that feels right... one of those lucky times where a company designs a product that is perfect for me without any modification