This is a classic case of a solution looking for a problem. I imagine that a Kindle would be a great companion on a plane, a train, or in a backpack, but other than that...
I can't imagine using one of these things at work or at home, where I do 90% of my reading. I love books. I have shevles full of them in my home and office. I love the feel and smell and the little notes I have written in them over the years. I love to see all of them on my shelves or just a few spread out on the bed or table. I love the manual process of leafing through them to scan, to retrieve, or for no reason at all. They are my friends, old and new.
If the purpose of the Kindle was to augment personal reading for travel, then great. But to be "better" than books, never.