Amazon Kindle review
I received my Kindle back almost a year ago, and have used it daily. I won't comment much on the hardware except to say the e-ink screen looks nice, works fine, and the form and weight factors are very convenient.
The killer feature in my opinion is the ability to pick samples from amazon.com, have them sent to your device and finally one-click buy/download the full book, from the device, if it pleases you.
That said, the current page in the sample is lost when you upgrade to the full book (you have to manually get back to the same location, which is pretty annoying).
The main limitation is the primitive formatting capabilities. This means that technical books (with code, maths, tables or diagrams) are not as well suited. I'm thinking I'll get a letter size e-ink device (once one becomes available) for full-size PDFs.
It's also not so good with non-english books/documents (Amazon, please start selling french books too).
I've had some success with importing my own docs using mobipocket creator, but the experience for non-official content is not ideal. There is also no way to generate the Kindle's proprietary audiobook format.
More generally, with Kindle books (and DRM), I miss the ability to lend or give a book to a friend after reading it. Accordingly, I wish the Kindle books would get a larger discount off their paper counterparts.
Internals:
It is striking to look at pictures of the Kindle taken apart, and compare them to shots of the iPod Touch or the MacBook Air.It's pretty obvious that Amazon could use some of that Apple know how ;-)
Update (2009/03/01):
The v1.2 firmware update lets you conveniently delete content from the Home screen using the backspace key.I posted a review of the Kindle 2 for comparison.