Best. Tech. Device. Ever. Amazon Kindle Paperwhite does what the 2011 Kindle I had, but with two significant upgrades; there is a touch interface (meh, not that interesting), and a built-in light! Yes, killer feature spotted!
Through some fancy technology, Amazon has managed to integrate a light into a device that does what it promises, consistently. So they were a bit behind the curve, but I think their implementation is very slick.
The device is still light (although feels heavier than the 2011 version), but the grain on the new leather cover is awesome, the magnetic click on/off is cool (although its annoying that you can't switch it off), but its the light that is the killer feature.
I bought the 3G version, which was probably a bit silly. Should have saved some money and bought the 3G version with ads / specials. You only see those on the "sleep" screen, which on this device you never see because it auto sleeps and wakes when you open and close the lid anyway. Not sure if it would be different if you had the ad-supported version.
But overall, a real winner. Does what it says it does, and does it well!