The Kindle is one of those devices that you often forget exists. Not in a bad way, and not because it isn't great. It's just one of the few devices left in the world of technology that is exceedingly simple and does one thing very well.
There is simply no better e-reader, period.
First up is a new feature called "PagePress" which lives in the edges of your Kindle and responds to subtle increases in pressure to turn pages. It's not a button, and there are no moving parts. It's simply a pressure sensor with haptic feedback. No more touching the screen to turn the page.
Second is an all-new high resolution 300 ppi display. The Kindle has always had great displays, but this is another level of resolution that is likely all but indistinguishable from a printed page. On top of that display is the front-light technology from the Paperwhite, but now it automatically adjusts to ambient light thanks to a light sensor on the upper left corner.
Lastly, this is the thinnest Kindle ever made at just 7.6mm. They've come a long way in making the Kindle "disappear" in your hands as you're reading, and making it so thin and so light really makes a difference.