For years, I've argued against the need for a Kindle. I could read books on my Treo years ago. Now I read them on my iPhone or iPad. I also get distracted by shiny things when I'm reading on my iOS devices.
Besides being drastically lighter, the Kindle offers no distractions. You can read on a Kindle, and that's it.
The last thing holding me back lately has been the lack of a lit screen. Much of my reading is done in bed at night, where a dark Kindle screen is useless. That problem goes away with the Kindle Paperwhite.
At $119, it's almost an impulse purchase. It'll sync with my current collection of Kindle books1 and let me read until my eyes bleed. No distractions. No worrying about preserving the battery.2 Just reading.