I hate it how everyone focuses on Amazon's Kindle. I think it's one of the weakest ebooks out there. And certainly the most proprietary. There are tons of ebooks out there: http://en.wikipedia.org/wiki/Ebook_reader and I think the iLiad should get more headlines: http://en.wikipedia.org/wiki/ILiad
I think it's clear that none of the currently released products are anywhere near ideal and are all lacking basic features and poor design trade-offs. One company needs to come in from left-field and shake up the market with an overwhelmingly better product.