At the moment, it looks like the Lytro is a rich person's toy—it costs 400 to 500 dollars—but it really does look like this could wind up changing photography forever. Here's the most promising bit from the Verge review:
We got to see a few of the company’s next developments, like a 3D view and a view that lets you pan inside an image and slightly change the perspective. Both are absolutely wild — as you pan around an image, people’s reflections on a glass of water shift to match your new perspective, as if you were moving your head slightly — and both will be rolled out to Lytro owners without any new hardware required. My hunch is that some of the camera’s bigger problems, like its low-light performance, will require new and more powerful hardware — a better processor, improved microlenses, and the like — but if you buy the Lytro, you’re buying a camera that’s definitely going to get better with time.
This technology shifts a photograph from a 2D representation of a moment in time into something much more fluid. Eventually, photographs will basically be slivers of time that you can navigate around in, and today's photographs will look as primitive and quaint as early daguerreotypes do to us now.