I'm not one to use cases, much less review them, so I'm not the best choice for this. But I do have a nitpicky nature, so at the very least I can tell you if the device they shipped matches the demo units.
It does. The construction is quite solid. It's a little on the heavy side, but I expected that (the solar panel and battery add weight). It has a faint whiff of that "new pleather" smell that we all love, but that's the only problem. The solar panel seems well attached, the plastics used to make the case feel solid, and the LED light works well.
Now, one of the important details with any gadget review is the battery test. That will be a little difficult here; this case has both a battery and solar panel. At this point there is a good chance that I might never have to plug it in again for the life of the device.
I think this case does live up to the demos. You can find it on Amazon (and elsewhere), where SolarFocus is selling it for $80 ($20 more than Amazon's own lighted case.)
Note that this case only fits the K4, not the K3 or Kindle Touch (coming soon).
There's a gallery below showing a few shots of the case; if you'd like to see more, here are the ones I took at CES.