No, it is not a revolution, it is a toy. IQ-wise it is competing with mobile phone cameras.
The Personal Computer (in its generic sense) started as a toy, too, and look what happened to the "real" computers.
The question is not whether, in its current, first incarnation it is a threat to the DSLRs or P'n'S cameras, the question is, extrapolating another 10 years of technological progress â€” is there any inherent reason that it will not be usable by Pros?
The digital camera and the phone camera initially got laughed at, too, because they started really low down, and look what happened to them...
Just by the way the technology is working the IQ of the Lytro will always be far lower than what you would get with a regular camera with the same sensor size. So no matter how much technology advances, the 'normal' technology will be ahead. Now it might be that at some point the sensors will get so good that the drop in IQ and resolution wont matter, but I do not think this will ever happen. Problem there is that at some point you will simply reach the limit of what is physically possible due to the way light behaves, and I don't think we are that far away from that border anymore.
Let me reformulate and use a different analogy. Nowadays most cameras don't have an optical viewfinder, because although the alternatives are not (yet) better, they are good enough for most people. Does this technology have the potential to become good enough and cheap enough to take over the point'n'shoot market (or what's left of it after the phones finish eating it for lunch)? Or will it be integrated into a phone too? ;-) What about EVIL or DSLR? Or will the new world be lightfield for the masses and DSLRs for the relative niche of ambitious and professional photographers?