First people, please don't mention the Kindle and the future-of-print in the same breath. That would imply that one has something to do with the other and why do Amazon's marketing for them?
But ignoring that for a moment, I think the whole concept of a dedicated "ebook" reader is somewhat dodgy. I mean, if that's all they do, why bother?
You can't copy out bits and pieces of the text, import them into something you're working on, share them with friends, blog about them -- or do any of the million other things you're used to doing on electronic devices that are increasingly just as small and inexpensive.
In other words, an 'eBook' reader completely sucks as an 'eBook' reader because it treats what you're reading as a complete digital dead-end.
Unfortunately, EVERY device sucks as an eBook reader. Laptops are awful, the screens on iPhones/PDAs are too small to read anything, LCD screens are awful to read from, especially in daylight, and the power needs of LCD screens make them non-viable for reading.
eBook readers with eInk are heading in the right direction; very thin and light, very long battery life, and passive displays. Passive displays are critical. The problem with the current eBook readers is they cost too damn much, and getting content is a minefield of incompatible formats.
Everyone will maintain that eBooks will never succeed until someone makes 1 good eBook reader. At that point, they'll sell like hotcakes, like the iPod did.