I just put down my slide rule so that I could write this post. I ordered a Lytro yesterday. Given all I spend on camera equipment, paper, and ink in a year, $500 for what looks like an entirely new technology seemed very little.
Will Version 1 replace DSLRs? No way, for many of the reasons written already. But there seems to be something threatening to the pros and hobbyists about anything that permits the masses to create anything comparable to what the pros and hobbyists create. But what is going to keep this technology moving forward if it shows promise is not the pros and the hobbyists. Its the ad agencies, newspapers, magazine editors, and other consumers of photographs that will drive the adoption. If there is a better and cheaper way to get the job done, they will gravitate in that direction. We all say it comes down to vision, composition, and creativity. It most certainly does, but if a music reviewer can get a great photo, you can bet the newspaper won't send a photographer.
I suspect that once people look at the technology, they will find all sorts of way to use it for fine art and creative ways. Cameras are tools and my experience is that no matter what the tool, creative people find unintended ways to "misuse" it to obtain creative results.
The fundamental question comes down to this: If you had a fantastic idea and opportunity to take the photo of a lifetime, is the photo any less fantastic because it was easier than some other way or that others could do the same thing? What then is a great photo? Is it in the eyes of the maker or the viewer?
In my view, new technologies equals new opportunities. But no matter. People are still happily using film, Holgas, and view cameras and having a lot fun doing so. You will still be able to use your DSLR once the Lytro comes out. And you can still play your vinyl records. The Lytro is the perfect device--it keeps forums like this one going.
I will be curious to see whether Really Right Stuff makes a plate to mount the Lytro to one of its tripods. That is the advanced hobbyist in me speaking.