The Kindle Paperwhite's screen is so awesome you wouldn't believe it's e-ink. Hell, I just saw it and I still don't believe it. It combines the paper-like text of e-ink screens with the usability of LCD screens but none of the eye strain. No other e-reader even comes close to this right now.
It's not just the screen either; the new Kindle Paperwhite makes the old Kindle look downright cheap. The obscenely clean black buttonless bezel of the Kindle Paperwhite makes a mockery of the old Kindle's painted plastic. E-readers should have always looked like this. The new Kindle Paperwhite is ever so slightly smaller than the old Kindle but it's hardly noticeable when you hold it in your hand. The weight seems to be about the same too.
But the screen. Oh, the screen. It's crisp, clear and delightfully bright without feeling like you're burning your eyes with liquid crystal daggers. The light is dispersed evenly throughout, making it feel more like a LCD/E-ink love child than an e-ink screen trying to fake the funk. The front-lit display in the Nook Simple Touch with Glowlight's looks like a splotchy birthmark in comparison.
The feel of the new Kindle is really great. There are no weak points, no creaky plastic—it's as nice as the older model but slightly better to touch. Using it is significantly more pleasant because the screen's refresh rate is so much faster and the touchscreen has been upgraded to capacitive. There's still a slight lag but that's because the E-ink screen still needs a little more time to refresh (when compared to LCD). Oddly, there doesn't seem to be a headphone jack on the new Kindle.
Amazon has also built, basically, an iPad Smart Cover for the Paperwhite. It uses a magnet to automatically wake it from sleep when the case is opened. And for what it's worth, it looks a lot nicer than the one that came with the touch last year.